E3switch Ds3 Owner's manual

PPPoE Ethernet to

Single/Dual DS3/E3

Network Extender

March 1st, 2015

Operating Information

Legal Preface:

All other product names mentioned in this manual may be trademarks or registered trademarks of their

respective companies.

LIMITED WARRANTY

E3Switch LLC (E3Switch) guarantees that every unit is free from physical defects in material and

workmanship under normal use for one year from the date of purchase, when used within the limits set forth

in the Specifications section of this User Guide. If the product proves defective during the warranty period,

contact E3Switch Technical Support in order to obtain a return authorization number. When returning a

product from outside of the United States of America, clearly state “NOT A SALE. RETURNED FOR

REPAIR” on the commercial invoice; and failing to do so, the customer will be responsible for imposed

duties and taxes. All customers are responsible for shipping and handling charges for returned items.

IN NO EVENT SHALL E3SWITCH'S LIABILITY EXCEED THE PRICE PAID FOR THE PRODUCT

FROM DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

WHATSOEVER (INCLUDING BUT NOT LIMITED TO LOST PROFITS) RESULTING FROM THE

USE OF THE PRODUCT OR ITS DOCUMENTATION, EVEN IF E3SWITCH HAS BEEN ADVISED

OF, KNOWN, OR SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAMAGES. E3Switch

makes no warranty or representation, expressed, implied, or statutory, with respect to its products or the

contents or use of this documentation and specifically disclaims its quality, performance, merchantability, or

fitness for any particular purpose. E3Switch reserves the right to revise or update its products or

documentation without obligation to notify any individual or entity. Please direct all inquiries to:

E3Switch LLC

412 N Main St Ste 100

Buffalo, WY 82834 U.S.A.

http://www.ds3switch.com, support@ds3switch.com

TEL: +1-650-241-9941

FCC STATEMENT

This device complies with Part 1 of the FCC Rules. Operation is subject to the following two conditions:

1. This device may not cause harmful interference.

2. This device must accept any interference received, including interference that may cause

undesired operation.

Note: This equipment has been tested and found to comply with the limits for a Class A digital device,

pursuant to Part 1 of the FCC Rules. These limits are designed to provide reasonable protection against

harmful interference when the equipment is operated in a commercial environment. This equipment

generates, uses, and can radiate radio frequency energy, and if it is not installed and used in accordance with

the instruction manual, it may cause harmful interference to radio communications. Operation of this

equipment in a residential area is likely to cause harmful interference, in which case the user will be

required to correct the interference at his own expense.

INDUSTRY CANADA NOTICE

This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus

set out in the Radio Interference Regulations of the Canadian Department of Communications.

Le present appareil numerique n'emet pas de bruits radioelectriques depassant les limites applicables aux

appareils numeriques de la class A prescrites dans le Reglement sur le brouillage radioelectrique edicte par

le ministere des Communications du Canada

EUROPEAN UNION (EU) STATEMENT

This product is in conformity with the protection requirements of EU Council Directive 89/336/EEC on the

approximation of the laws of the Member States relating to electromagnetic compatibility. The

manufacturer cannot accept responsibility for any failure to satisfy the protection requirements resulting

from a non-recommended modification of the product.

This product has been tested and found to comply with the limits for Class A Information Technology

Equipment according to CISPR 22/European Standard EN 022. The limits for Class A equipment were

derived for commercial and industrial environments to provide reasonable protection against interference

with licensed communication equipment.

Attention:

This is a Class A product. In a domestic environment this product may cause radio interference in which

case the user may be required to take adequate measures.

International Electrotechnical Commission (IEC) Statement

TABLE OF CONTENTS

CHAP ER 1: DESCRIP ION AND REQUIREMEN S .............................................................................................. 6

CHAP ER 2: QUICK SE -UP .............................................................................................................................. 6

CHAP ER 3: FRON PANEL ............................................................................................................................... 8

FRONT PANEL INDICATORS ............................................................................................................................8

CHAP ER 4: REMO E MANAGEMEN H P AND SNMP ............................................................................... 8

UNIT'S IP/MAC ADDRESS .............................................................................................................................8

Automatic Link-Local IP Address.........................................................................................................9

Initial Numeric IP Address....................................................................................................................9

Unknown IP Address Recovery............................................................................................................9

MANAGEMENT PASSWORDS ...........................................................................................................................9

SECURITY ....................................................................................................................................................10

HTTP Interface Security.....................................................................................................................10

SNMP Security....................................................................................................................................10

HTTP MANAGEMENT ................................................................................................................................10

Event Log File.....................................................................................................................................11

Resetting..............................................................................................................................................11

SNMP ........................................................................................................................................................11

UPGRADING FIRMWARE ...............................................................................................................................11

FEATURE ACTIVATION/UPGRADE .................................................................................................................11

CHAP ER 5: OPERA ING MODES AND CONFIGURA ION ................................................................................. 12

TELECOM ....................................................................................................................................................12

Clock Source.......................................................................................................................................12

DS3 Circuit ID PMDL........................................................................................................................12

PACKET FLOW .............................................................................................................................................13

PORT TO PORT PACKET FLOW .....................................................................................................................13

LAN-to-LAN.......................................................................................................................................13

Forwarding..........................................................................................................................................13

Loopback.............................................................................................................................................13

LAN PORT SETTINGS ..................................................................................................................................13

LAN Port Speed..................................................................................................................................13

Autonegotiation Problems...................................................................................................................14

SFP Second LAN Port........................................................................................................................14

Dedicated Management/PPPoE-Data LAN Ports...............................................................................14

VLAN ........................................................................................................................................................14

VOIP / VIDEO OR HIGH-COS PRIORITY FRAMES ..........................................................................................14

PORT AUTO-DISABLE AND RETURN-TO-SERVICE DELAY ..............................................................................14

DS3/E3 Return to Service delay..........................................................................................................1

LAN Auto-Disable..............................................................................................................................1

CHAP ER 6: IN EROPERABILI Y ..................................................................................................................... 15

LAN ..........................................................................................................................................................1

Autonegotiation problems...................................................................................................................1

SFP LAN Port 1..................................................................................................................................1

Pause Frames.......................................................................................................................................16

VoIP / Video or High-CoS Priority Frames........................................................................................16

TELECOM/WAN .........................................................................................................................................16

FIBER/COPPER MEDIA CONVERTERS ............................................................................................................16

ROUTERS AND SWITCHES .............................................................................................................................16

CHAP ER 7: ELECOM CONNEC IONS ............................................................................................................ 16

FRAMING AND PHYSICAL LINK ....................................................................................................................16

TELECOM CABLING .....................................................................................................................................16

CHAP ER 8: LAN CONNEC IONS AND PERFORMANCE ................................................................................... 17

LAN PORTS ................................................................................................................................................17

AUTONEGOTIATION ......................................................................................................................................17

LAN CABLING ............................................................................................................................................17

LAN BUFFERING, LOADING AND FLOW CONTROL ........................................................................................17

LAN PACKET PRIORITY ..............................................................................................................................18

TCP/IP AND GENERAL PERFORMANCE TUNING ...........................................................................................18

CHAP ER 9: DS3 PACKE S AND LINK OPOLOGY ......................................................................................... 18

LINK BIT-ERRORS .......................................................................................................................................18

CHAP ER 10: ROUBLESHOO ING .................................................................................................................. 18

GENERAL ....................................................................................................................................................18

LOOPBACK OF DS3 .....................................................................................................................................19

Terminology........................................................................................................................................19

Limitations...........................................................................................................................................19

Alternatives to Loopback....................................................................................................................20

Initiating Loopback.............................................................................................................................20

PERFORMANCE ............................................................................................................................................21

INTEROPERABILITY ......................................................................................................................................21

LABORATORY TESTING ................................................................................................................................21

PINGING ......................................................................................................................................................21

STEP-BY-STEP DIAGNOSIS ...........................................................................................................................22

CHAP ER 11: HIRD PAR Y COPYRIGH NO ICES ........................................................................................ 24

ECOS LICENSE .............................................................................................................................................24

THE FREEBSD COPYRIGHT .........................................................................................................................24

THE NET-SNMP COPYRIGHT ......................................................................................................................24

THE APACHE LICENSE .................................................................................................................................2

THE SHA2 COPYRIGHT ...............................................................................................................................26

THE BZIP2 LICENSE ...................................................................................................................................27

THE ATHTTPD LICENSE ............................................................................................................................27

CHAP ER 12: ECHNICAL SPECIFICA IONS AND S ANDARDS ......................................................................... 28

Chapter 1: Description and Requirements

Chapter 1: Description and Re uirements

The E3Switch converters described herein are used individually to connect a customer's Ethernet LAN to an

ISP offering PPP over full or fractional/subrate DS3. The LAN interface is PPPoE RJ4 100/1000BaseTX

copper or SFP 1000BaseX fiber optic. The telecom link must be point-to-point and may support either

framed or unframed data. For point-to-point links without the overhead of PPPoE, consult our other

product documentation.

For ease of installation, the converter requires only minimal configuration setup via HTTP – typically

setting the CRC-length and scrambling state – and will then work immediately upon connection of LAN and

telecom cables.

The hot-swappable converter card draws a minimal amount of power and may be purchased in a variety of

chassis. Standalone, single units ship in high-reliability, fan-free 1U chassis with rackmount brackets and

are available in a 100-240VAC or a ±3 -7 volt DC models. NEBS-III, redundant-power multicard chassis

are available in 6-slot/1U and 20-slot/3U versions.

The converter contains both an 8P8C(RJ4 ) LAN port and an SFP LAN port, allowing either optical or

copper LAN connectivity and HTTP or SNMP management of the converter either in-band or out-of-band.

Remote firmware upgrade to a converter is possible through either the LAN or DS3/E3.

The converter will buffer data, and implements flow-control and quality-of-service mechanisms to eliminate

data loss.

The converter can generate its own DS3/E3 transmit clock or use the incoming DS3/E3 received clock.

The converter will pass all PPPoE error-free packets unaltered which do not exceed 9600 bytes in length.

This included stacked-VLAN, QinQ frames and all modern router protocols.

The converter has been designed with attention paid to maximum throughput, minimum latency and

minimal packet loss. The converter is often both a cost-effective and bandwidth-efficient alternative to

routers. Even when connected to a LAN port from a router, eliminating a router telecom card can free up

expensive, limited, router backplane bandwidth .

The converter is plug-and-play and can often be installed in several minutes. Network topologies and

configuration settings of equipment connected to the converter can be complex, however, so additional time

should be allocated to achieve a properly functioning system.

Chapter 2: Quick Set-up

•Attach E3Switch converter to DS3 BNC cable from ISP.

•Set CRC-length, scrambling-on/off, framing-type, DS3-rate via the HTTP LAN interface.

•Connect the PPPoE LAN-port of your equipment to either LAN port of the converter.

A connection from your PPPoE equipment to the ISP via username/password login with a blank session

name should now be possible.

In detail:

Attach the converter to a power source. The front panel lights should illuminate. Green is normal; orange

indicates an error.

Chapter 2: Quick Set-up

Attach an Ethernet UTP cable from the PPPoE LAN port on your equipment to the RJ-4 LAN Port 2 of

the converter. The converter can perform automatic cross-over vs straight-through cable adaptation. The

LAN 2 light will change from orange to green if a properly negotiated Ethernet link has been established,

but does not indicate PPPoE connection status. he network equipment attached to the LAN port of the

converter should be set for autonegotiation mode in order to allow the converter to negotiate a

100Mbit full-duplex connection. Disabling autonegotiation or using old LAN equipment may result in the

attached LAN equipment configuring to half-duplex mode, resulting in CRC errors and packet loss. Refer

to the interoperability section of this document for more information. o support PPPoE packets greater

than 1500-bytes, the LAN connection must be GbE/GigE/1000Base X rate.

Typically, set the PPPoE LAN port speed to GigE 1000Mbit/s to allow packet-lengths greater than 1 00-

bytes and up to 9600 bytes. Set the management LAN port speed to 100BASE- X to avoid DMA

underflow/overflow errors of the converter.

Attach two 7 -ohm coaxial cables from either the Port 1 or Port 2 BNC connectors of the converter to the

input and output connectors of your E3 or DS3 link. Once each converter is receiving a valid signal from

the remote partner, the DS3/E3 Port LED will change from orange to green. This indicates that the

converter has achieved proper sync lock with the remote ISP, but does not indicate PPP session status or

proper settings of CRC-length or scrambling or framing.

Refer to the management chapter of this manual for HTTP connection instructions. If these values have not

been provided by the ISP, simply trying different combinations and monitoring the HTTP or SNMP error

status counters of the unit will typically suffice.

At the bottom of the administration page, decide which LAN ports you intend for PPPoE data and which for

HTTP/SNMP management of the converter and set appropriately. This is not mandatory, but you will see

some management packets on the PPPoE LAN if that LAN port is not set for PPPoE only.

Connect the PPPoE LAN port of your local host or router to the E3Switch converter. The user-name and

password for your PPPoE are provided by the ISP and are not relevant to the converter; however the

session-name for the PPPoE connection must be blank or empty.

The HTTP status screen of the converter will indicate whether the PPPoE connection is active or

unconnected. PPPoE packet exchange is indicated in the log found at the bottom of the HTTP settings

screen. If the packet exchange appears valid but the link is terminated shortly thereafter, ensure that your

PPPoE equipment's setting for username, password and IP address (fixed vs. DHCP) are correct. All can

terminate a PPPoE session shortly after initiation. A valid PPPoE connection handshake appears as follows:

Event age, most recent first...

days h:m:s event

Age 0d 0:00:02> DS3/E3 Ports O

Age 0d 0:00:03> PPP is UP - session ID 0xa1b5

Age 0d 0:00:03> Sending PADS session confirmation

Age 0d 0:00:03> PPP PADR msg received from 00:13:46:88:09:3e

Age 0d 0:00:03> Sending PADO offer on 8P8C LAN Port2

Age 0d 0:00:03> PPP PADI msg received from 00:13:46:88:09:3e

Age 0d 0:00:03> SFP LAN Port1: UP

Age 0d 0:00:04> 8P8C LAN Port2: UP

Refer to the management chapter of this manual if HTTP or SNMP operating statistics are desired or to

change the default administrator password. Changing the default password is highly recommended to

allow ongoing configuration changes. When the password has not been changed from default,

configuration changes are prohibited for security reasons after 5 minutes after any new power cycle.

Simply power cycle again to change the password – if the unit is still in your possession and the link is

not passing important data.

There is no further configuration or setup required for the converter.

Chapter 3: Front Panel

Front Panel Indicators

All Indicators: Green indicates normal operation.

Orange indicates an error condition.

Black indicates a disabled port.

DS3/E3 1/2: Green if the unit has synchronized to a valid carrier signal pattern from the remote unit and data can

be transferred on the link. Does not indicate PPP or PPPoE session status.

Flashes black each time a packet is received on this port.

Orange indicates no valid connection or loss of receive sync with remote unit.

Flashes orange/green if incoming signal is OK but either looped back or PPP session down..

Flashes orange/black if link is OK but waiting in a configured return-to-service delay period.

BER: Green if OK.

Orange flash for each BPV bit error.

Orange steady for absence of DS3/E3 receive signal, loss of frame lock onto receive bit-stream,

drive-level fault on transmit cable, or excessive receive bit errors.

Note: In a dual DS3/E3 unit, the BER will reflect the status of the operational link if one fails.

LAN1/2: Green when a properly negotiated 100/1000BaseTX Full-Duplex or SFP LAN connection exists.

Does not indicate PPPoE session status.

Flashes black each time a packet is received on this port.

Orange indicates no valid connection.

Flashes orange/black if in a configured “down if telecom down” mode.

Chapter 4: Remote Management HTTP and SNMP

Unit's IP/MAC Address

The source Ethernet MAC address of E3Switch converters is 00: 0:C2:6F:xx:xx. The converter's current

IP and MAC addresses are always both shown at the HTTP management screen.

The unit's management interface can be initially contacted at either its automatic link-local IP address

e3switch.local as described below or at its initial numeric IP address described below. Note that after initial

setup, an operator may have changed the contact IP address to a new value and the initial addresses below

may not work. Prior to operator reconfiguration the unit will respond to HTTP, SNMP and ping requests to

its initial IP address.

For initial communication with the converter, it may be necessary to set the network address of the host port

communicating with the converter to 169.2 4.xxx.xxx with subnet mask 2 .2 .0.0. For security, routers

are advised not to forward packets with these link-local IP addresses, so a direct connection is advised.

Once initial contact has been established with the HTTP management interface of the converter, the

converter's IP address can be set to a new, static value if desired.

If a unit's operator-configured IP address is lost or forgotten, it can be recovered as described later in this

chapter.

Chapter 4: Remote Management HTTP and SNMP

Other than the e3switch.local addresses described below, all IP addresses used within the converter's

management interface must be in xxx.xxx.xxx.xxx numeric format rather than a human-readable DNS-

resolvable hostname.

Automatic Link-Local IP Address

E3Switch converters are shipped with an initial IP address that conforms to recent zero-configuration link-

local standards. This allows multiple E3Switch converters on the same IP network to initialize with unique

IP addresses without conflict and allows simple ping/HTTP/SNMP access to the converters using

hostnames e3switch.local or e3switch-2.local,... provided that the free ZeroConf mDNS software has been

installed on the machine attempting to communicate with the converter. Do not prefix www. prior to

e3switch.local. www.e3switch.local will not work.

The converters negotiate between themselves to determine which converter is assigned name e3switch.local

and which receives e3switch-2.local and so on. Since the assigned name will not necessarily be fixed to a

particular converter after power cycles, the system manager will probably want to use/set the converter's

numeric IP address sometime during or after initial installation.

Web descriptions are available for ZeroConf mDNS and Link-local IPV4LL ip addresses. Free ZeroConf

software such as Bonjour for Windows or Avahi is available for Windows/Linux/Unix machines.

Initial Numeric IP Address

When received from the factory, the converter can also be contacted at its initial default IP numeric address

which always takes the form 169.2 4.aa.bbb. Units can be initially contacted at this IP address where

aa.bbb matches the serial number listed on the front label.

The converter's current IP and MAC addresses are both shown at the HTTP management screen.

Unknown IP Address Recovery

The following methods may be used to determine a converter's IP address if lost or forgotten. Note that

once determined, management communication may only be possible from the same IP network if the

converter's default router address is invalid.

Unplug all LAN and BNC cables from the converter and power cycle the unit. 30 seconds after power-up,

the converter will begin blinking out its IP address on the leftmost LED. Each digit is counted up as an

orange blink with a pause between digits and a short blink for a 0. A decimal in the IP address is indicated

with a green blink. For example, <orange><orange><pause><short-orange><pause><green>... would be

an IP address that begins “20.”

For those with access to packet sniffers, upon power-up, the converter will broadcast several gratuitous

ARP packets on its network ports which can be examined with a sniffer or packet monitoring software to

determine a unit's IP address. The source Ethernet MAC address of such packets and E3Switch converters

is 00: 0:C2:6F:xx:xx. Tcpdump or Wireshark are two readily available software packages to examine

network packets.

Additionally, examination of the MAC address table of an attached LAN switch or router may provide the

IP address if the E3Switch MAC address prefix (00: 0:C2:6F:xx:xx) can be located.

Management Passwords

The HTTP management statistics page is initially accessible without a password. The HTTP settings page

is initially accessible within the first several minutes after power-up with username admin and no password.

If the unit has not had its default password changed, after several minutes the settings page will be locked

for security reasons. It is desirable to change the default password of the unit. For security reasons,

changing the default password of the unit must be done within the first several minutes of power-up. If the

HTTP management password is lost or forgotten, it may be reset by accessing the HTTP management

settings within the first minute after power-up and with no BNC cables attached to the unit.

Chapter 4: Remote Management HTTP and SNMP

SNMP statistics may initially be accessed using the read-only community name public. Write-community

names and variable access authorization may be set through the HTTP management interface.

Security

Please also refer to the password section above.

HTTP Interface Security

Access to the HTTP management interface statistics and settings pages can be selectively limited to users

knowing the HTTP management password, which is transmitted securely on the network using MD

encoding. New values of management settings, or modifications of the administrator password are not

encrypted and are visible to users monitoring network packets, as is statistical data requested by an MD

authorized user or any information visible on a HTTP page.

When logging out from any secure webpage, the browser window should always be closed! Browsers

typically continue to send administrator credentials continuously even after apparent logout.

SNMP Security

The converter implements SNMPv2c, which is inherently an insecure protocol; however, the converter

enhances security by implementing view-based access management (VACM), which can restrict read or

write access to specific management settings and statistics. When shipped, the converter allows read access

to “safe” SNMP statistics and prohibits read and write access to statistics and settings which could allow

determination of network topology or interfere with normal link traffic. The VACM configuration can be

updated through the HTTP management interface to meet the user's needs, and most SNMP variables can

also be set through the HTTP management interface in a more secure manner than SNMP allows.

– SNMP VACM Security Warning –

As shipped, the default “safe_ro_view” is secure but not private.

View based access model VACM for SNMPv2c provides good restriction

of access to only specified statistics but no data privacy and

minimal user authentication. When a specific variable is enabled

for reading or writing, from a security perspective it should

be considered either public for reading or public for writing.

Alternatively, most configuration parameters can be set through

the HTTP password-protected interface which is secure.

Viewing snmpd.conf exposes it and community names to visibility by

3rd party network sniffers. All SNMPv2c data on the network

is visible. All community names can be "guessed" and, when used,

become visible to sniffers. Source IP addresses of requests

can be forged. Enabling a write community should be considered

insecure with respect to the specific view variables enabled.

Variables in the groups: interface, ds3, dot3 & mau, control the

link datapath; allowing write access allows disabling the link.

Specific variables disabled for all write users are secure.

Specific statistics disabled for all read users are invisible

and secure.

HTTP Management

The converter contains a comprehensive, user-friendly HTTP management interface which allows a

manager to monitor bit-error-rates on the DS3/E3 link, lost packets, and user-friendly status messages at a

single, color-coded HTTP screen. A screenshot is available at www.e3switch.com. Most settings that can

be modified via SNMP can also be set through the HTTP interface in a more user-friendly manner.

Refer to the configuration section of this document for guidance on specific settings.

Chapter 4: Remote Management HTTP and SNMP

vent Log File

A timestamped log of operating status and events may be accessed at the HTTP management administration

page.

Resetting

Two options for resetting the converter may be accomplished at the HTTP management administration

page. A management software reset will reset counters, statistics, MIB variables, and management software

of the converter without interrupting data flow across the link. A hardware reset will temporarily interrupt

link data flow as if the converter had experienced a power cycle. For new functionality to take effect, a

hardware reset is required after upgrading firmware but need not be initiated immediately. A software reset

is not appropriate after upgrading firmware, as only the management CPU would be reset while the packet

transfer CPU would be operating with the older, incompatible version of firmware.

SNMP

The converter contains an SNMP agent which can respond to version 1 and version 2c requests for network

statistics from remote SNMP clients. The agent can also generate notifications of important network events

such as when network ports go up/down or experience high error rates. These trap notifications can be sent

to multiple hosts if desired, and using free or commercial software, the receiving hosts can log the

notifications or even generate email or pager messages for network managers.

SNMPv2c is inherently an insecure protocol, so the converter implements VACM to restrict access to

“safe” statistics and settings. Please refer to the security discussion section of this document.

SNMP configuration of various parameters such as community names and trap destinations is accessed

through the HTTP management interface and is implemented as a configuration file having an snmpd.conf

structure. Snmpd.conf is described by third parties in publicly available documents.

Statistics and settings accessible via SNMP are called MIB-variables and are organized in a hierarchical

tree topology. The MIB variable trees implemented by the converter include recent versions of the DS3/E3,

interface, MAU, dot3, and many of the typical IP-network MIB trees. The full list of MIB trees available is

listed by viewing the system.sysORTable of the converter. As mentioned earlier, access to certain trees or

variables is initially disabled for security reasons, but can be set as the user wishes through the VACM

settings. The converter can typically return 1000 MIB variables per second in bulk requests and support

SNMP response message sizes up to 000 bytes.

Upgrading Firmware

For activation of additional capabilities of the converter, see the “Feature Activation” section. Feature

upgrades do not necessarily require a firmware upgrade.

Firmware upgrades may be transferred to the converter via the LAN port. A hardware reset, which will

interrupt link data flow for several seconds, will be required at some point after the transfer in order to

begin using the new firmware. Instructions for performing the TFTP transfer are included with all firmware

shipments. The most common source of problems when performing upgrades is attempting a TFTP transfer

in ASCII or text mode rather than binary or image mode, resulting in a “too large” or “out of room” type

TFTP error.

Feature Acti ation/Upgrade

For activation of additional capabilities of the converter after initial purchase, supply the factory with the

serial number from the front of your converter (also shown at the HTTP management page for recent

firmware) and purchase an alphanumeric “factory upgrade key” which is entered at the HTTP management

screen.

Chapter : Operating Modes and Configuration

Chapter 5: Operating Modes and Configuration

Telecom

There are several, low-level configuration settings for telecom ports:

●CRC-length (16bit, 32bit, or none)

●Scrambling (on or off)

●Rate (typically full rather than a sub-rate or fractional rate)

●E3 vs DS3

●cable length (for long DS3 runs only)

●M13 vs C-Bit (for DS3 only)

●Circuit ID message (for C-Bit only)

●Transmit clock source

Use a “DS3” configuration setting typically for North America, Japan, and South Korea; otherwise, “E3”

speed.

Incorrect WAN settings will typically manifest in the errored-packet counts shown at the HTTP

management screen of the converter.

The cable length setting will transmit a slightly stronger signal on long DS3 coax runs. The M13/C-Bit

setting sets the AIC bit in DS3 frames to either 0 or 1. This bit is typically ignored by the DS3 carrier;

however DS3 carrier equipment set to auto-sense the incoming DS3 framing type will need this setting to be

correct.

Clock Source

The transmit clock source is typically “local” for both units. Certain DS3/E3 carrier equipment or optical

converters require the same transmit clock in each direction; this may manifest itself as frame-slip errors. In

such a case, set one unit to “loop” clock source. In very rare cases the carrier DS3/E3 equipment will

generate the clock for the entire path, and each unit should be set to “loop”. Setting both units to “loop” is

typically inappropriate and can result in transmission failure if a master clock is not being generated by

carrier equipment. Without a master clock, two units set in “loop” mode will wander to an unspecified

clock speed, which is unlikely to meet DS3/E3 specifications.

Dual-channel DS3/E3 units allow Port 2 transmit clock speed to be derived from incoming Port 1 clock

speed. This is an uncommon configuration requirement and should typically be avoided.

In the event of incoming clock loss, the transmit clock will automatically switch to a locally generated

DS3/E3 clock source.

The receive clock speeds are shown at the bottom of the unit's HTTP management statistics page to assist

timing diagnosis.

DS3 Circuit ID PMDL

DS3 Path Maintenance Data Link (PMDL) identification messages associated with C-Bit framed DS3 links

can be received and transmitted if desired. Circuit ID messages convey human-readable, configurable,

physical location information of the DS3 source equipment. These messages are transmitted in the C-Bits

of the frame and do not decrease bandwidth available for data. PMDL Circuit ID messages facilitate

confirmation of the data source when presented with a pair of unlabeled BNC cables.

Chapter : Operating Modes and Configuration

Packet Flow

Port to Port Packet Flow

LAN-to-LAN

Certain firmware versions allow LAN-to-LAN packet flow to be enabled, if desired, in units where the

second SFP/LAN port has been enabled/purchased. LAN-to-LAN unidirectional flow for monitoring may

also be configured if desired.

LAN-to-LAN flow can result in dropped packets if the destination LAN port bandwidth setting is too low.

An example would be 2x 44Mbit/s traffic from a dual-DS3 and > 12Mbit/s traffic from the other LAN port

exceeding 100Mbit/s of a 100Base-TX LAN port which was receiving both DS3 and LAN-to-LAN traffic.

The unit will attempt to preserve incoming DS3/E3 packets while dropping LAN-to-LAN packets in such

an instance.

LAN-to-LAN should be used cautiously in combination with management or data-only LAN port settings.

The blocking of a subset of traffic can result in network and spanning tree topologies which can be

inappropriate or difficult to diagnose.

Forwarding

Once a PPPoE session is established, all PPPoE packets are passed from LAN to WAN unfiltered and

unmodified. All PPP packets from the WAN are passed to the LAN likewise.

Loopback

Certain firmware versions allow packet flow from DS3 ports to LAN to be configured to automatically halt

in certain situations in which the converter is receiving loopback data. The automatic loopback traffic

disable will only occur if the local converter has requested the remote to loopback. This occurs when an

SN P request sets the local converter dsx3SendCode variable to dsx3SendLineCode, which requests the

remote converter to loopback DS3 data received. DS3 loopback initiated by the carrier or any source

other than described above cannot be recognized as loopback data and the setting described will be

irrelevant.

LAN Port Settings

The following hardware for the two LAN ports exist on all converters shipped:

●GbE, GigE 1000Base-T for the RJ-4 LAN port2.

●Jumbo frames (9600 bytes).

●SFP LAN Port 1 which can accept optical or copper (100/1000) SFP transceivers.

●Either LAN port can be configured as a dedicated out-of-band management port if desired.

See the “Interoperability” section of this manual for information on packet lengths and detailed port

connection/autonegotiation discussion.

he autonegotiation mode of the converter must match the autonegotiation mode of attached LAN

equipment. If autonegotiation is enabled on the converter it must be enabled on the attached equipment. If

disabled on the converter, it must be disabled on the attached equipment. This requirement is necessary to

fulfill 802.3 standards which mandate a fallback to half-duplex operation if an autonegotiation mismatch

exists. The converters require full duplex to operate.

LAN Port Speed

Typically, set the PPPoE LAN port speed to GigE 1000Mbit/s to allow packet-lengths greater than 1 00-

bytes and up to 9600 bytes. Set the management LAN port speed to 100BASE- X to avoid DMA

underflow/overflow errors of the converter.

Chapter : Operating Modes and Configuration

1000Mbit/s is generally preferred over 100Mbit/s on the PPPoE port only, though it generates

significantly more power-requirements, heat, and radiated electromagnetic noise even in the absence of

packet flow. 1000Mbit/s may slightly reduce path latency, as an incoming LAN packet must be fully

received before being forwarded to an outgoing port. The latency savings to receive or transmit a 1 00-

byte packet at 1000Mbit/s vs 100Mbit/s speed is 0.108 milliseconds (1 00bytes/packet x 8bits/byte /

(100Mbits/s) - 1 00bytes/packet x 8bits/byte / (1000Mbits/s)).

1000Mbit/s LAN port speed may be desirable when one LAN port is configured to monitor the other LAN

port in addition to receiving incoming DS3/E3 data. In such a case, the data rate that the LAN port is

expected to transmit (the sum of all ports that could be a data source for the LAN port) may be greater than

100Mbit/s. The HTTP management statistics screen will show overflow errors if a port's data rates are

exceeded.

Setting more than one LAN port to 1000Mbit/s is not recommended and may result in

underflow/overflow errors in certain high packet load, memory-intensive cases.

Autonegotiation Problems

There are rare cases with older LAN equipment in which it may be necessary to disable autonegotiation. If

crc-errors or short packet errors are seen in the management statistics of the LAN port, the attached LAN

equipment has probably configured itself to half-duplex mode and colliding packets are being lost. In such

a case, autonegotiation should be disabled on both the converter and the attached LAN equipment, with

both forced to 100BaseTX full-duplex. Autonegotiation interoperability and standards were not well

understood by the industry at the inception of 100BaseTX, resulting in some older LAN equipment not

understanding the converter's autonegotiation advertisement of strictly full-duplex capability.

SFP Second LAN Port

The SFP LAN Port 1 hardware exists on all converters shipped and enables out-of-band management,

through either LAN port, or fiber-optic LAN connections of 10km or more. Refer to interoperability

section of this document for compatible SFP transceivers.

Dedicated Management/PPPo -Data LAN Ports

Either LAN port may be configured to pass all packets to DS3/E3 or, selectively, to pass only management

or only PPPoE data packets.

If a LAN port is configured for PPPoE-only packets, the unit will drop incoming management packets

destined for an E3Switch MAC address. This provides a moderate level of security. These packets and

management broadcast/multicast packets may not be forwarded to the second LAN if LAN-to-LAN traffic

is configured.

VLAN

As shipped, the unit will accept management packets with any VLAN tags and attempt to respond to the

same. For more robust performance, specific VLAN tag settings can be configured. These settings only

apply to packets to and from the converter's management entity.

VoIP / Video or High-CoS Priority Frames

In certain firmware, receive queue space is reserved in the converter to allow frames with high 802.1p class-

of-service (CoS) priority settings to bypass existing frames waiting to be transmitted to the DS3/E3. This

allows voice, video and other high-priority traffic to experience low-latency transmission. Firmware allows

the “high” CoS level to be configured. Most VoIP traffic is tagged at CoS or 6, so level is typically a

good setting for the high-CoS value.

Port Auto-Disable and Return-to-Ser ice Delay

In addition to manually configuring a port as disabled, the converter has the ability to delay a DS3/E3 port's

return to service for a specified period of time after it has failed or disable a LAN port if both telecom links

are down.

Chapter : Operating Modes and Configuration

DS3/ 3 Return to Service delay

The return-to-service delay prevents network topology thrashing if a telecom link is flapping up and down.

Some telecom carriers will interrupt service for 0msec, once per day as a link test. A configurable, failure-

time setting to prevent such tests from triggering a link-down, retun-to-service delay.

To exit the return-to-service delay, power-cycle the converter or click the button which appears on the

configuration HTTP screen of a converter that is in configuration delay.

LAN Auto-Disable

The LAN port can be configured to automatically disable itself when no telecom link exists. This setting is

useful for attached LAN equipment which requires the LAN port to go down in order to understand that the

path to the remote network is no longer available. Use this setting cautiously, as management of the

converter will also no longer be possible through a disabled LAN port.

To exit the LAN-port-disabled condition, power-cycle the converter, which will allow communication with

the converter for approximately one minute even if telecom ports are down.

Chapter 6: Interoperability

LAN

The LAN ports of the converter support, at a minimum, all 100BaseTX Full-Duplex Ethernet connections

up to maximum line lengths and are set to auto-MDI/MDIX to automatically detect/correct crossover vs

straight LAN cable and auto-negotiate full-duplex and pause frame modes with the attached LAN

equipment.

The converter will pass all un-errored packets which do not exceed 16 0 bytes in packet length (9600 with

jumbo frames enabled). This length allows QinQ, stacked VLAN, and extended packet-length router

protocols to be passed without concern. The management agent accepts and responds with packets having

MTU of 13 0 bytes in order to automatically allow room for security protocol overheads.

Autonegotiation problems

There are rare cases with older LAN equipment in which it may be necessary to disable autonegotiation. If

crc-errors or short packet errors are seen in the management statistics of the LAN port, the attached LAN

equipment has probably configured itself to half-duplex mode and colliding packets are being lost. In such

a case, autonegotiation should be disabled on both the converter and the attached LAN equipment with both

forced to 100BaseTX full-duplex. Autonegotiation interoperability and standards were not well understood

by the industry at the inception of 100BaseTX, resulting in some older LAN equipment not understanding

the converter's autonegotiation advertisement of strictly full-duplex capability.

It is highly desirable to leave autonegotiation enabled so that changing attached LAN equipment does not

result in the new equipment defaulting to half-duplex if set to autonegotiate.

SFP LAN Port 1

This port is designed to be compatible with inexpensive, high-quality, copper or fiber-optic, SFP

transceivers from Finisar, which allows LAN connections of 10km or more. Most other industry-standard

SFP transceivers will work as well; however, fiber-optic features such as temperature and optical

transmit/receive power and alarms will only be available if using Finisar transceivers. Non-Finisar copper,

RJ4 SFP transceivers may only operate in 1000Base-T mode, while recommended transceivers from

Finisar, and possibly Avago or 3Com will operate in 100Base-TX mode as well.

Chapter 6: Interoperability

Pause Frames

Unless disabled in the settings or through autonegotiation, the converter sends pause command frames to

attached LAN equipment when the converter's incoming LAN buffers become nearly full. The converter

ignores pause command frames sent to it.

VoIP / Video or High-CoS Priority Frames

In certain firmware, receive queue space is reserved in the converter to allow frames with high 802.1p class-

of-service (CoS) priority settings to bypass existing frames waiting to be transmitted to the DS3/E3. This

allows voice, video and other high-priority traffic to experience low-latency transmission. Firmware allows

the “high” CoS level to be configured.

Telecom/WAN

The converter can transmit over a variety of E3 or T3/DS3 links (with appropriate media converters) such

as fiber optic, microwave radio, laser, copper, satellite, or a combination; however, the attachment interface

is always via 7 -ohm copper coaxial rather than optical. The point-to-point telecom link must be

unchannelized, i.e., not subdivided into T1 or E1 channels. The telecom link may be either framed or

unframed and supports both M13, M23, clear-channel, C-Bit, and G.7 1 framing. C-Bit framing is

suggested for DS3 links.

Certain firmware allows subrate/fractional WAN connectivity.

Fiber/Copper Media Con erters

Transition Networks DS3/E3 Coax to Fiber Media Converter, SCSCF3014-100 has been reported to lack

the ability to properly maintain separate DS3/E3 transmit clock speeds in each direction and are not

recommended. This problem typically manifests itself as frame slips or loss of telecom signal lock in one

direction at a rapid, consistent periodic rate, which is proportional to the difference in clock speeds of each

telecom direction. If such media converters are already in use, setting the DS3/E3 transmit clock source of

one of the WAN units to “loop” may alleviate problems.

Routers and Switches

The configuration of routing tables of the PPPoE equipment attached to the E3Switch converter is beyond

the scope of this document.

Chapter 7: Telecom Connections

Framing and Physical Link

The converter can transmit the LAN data over a variety of E3, T3/DS3 links (with the appropriate media

converter) such as fiber optic, microwave radio, laser, copper, satellite, or a combination. The converter

may be used with a standard (i.e., M13, M23, clear-channel, C-Bit or G.7 1) framed or unframed, E3 or

T3/DS3 link with AMI and HDB3 or B3ZS encoding. The link must be unchannelized, i.e., not subdivided

into T1/E1 channels. C-Bit framing is recommended for DS3 links. Newer firmware supports PMDL

Circuit ID on C-Bit links.

Certain firmware supports sub-rate/fractional WAN.

Each converter generates the timing clock of its transmitted bit-stream, within E3 and T3/DS3 standards,

either locally, or locked to either port's received bit-rate. The incoming clock rates are displayed at the

unit's HTTP management page.

Telecom Cabling

For the E3 or T3/DS3 connection, two 7 -ohm coaxial cables (one transmit and one receive) with BNC

connectors are required at each end. It is important that 7 -ohm cable be used and not 0-ohm cable. For

long connections or in electrically noisy environments it may be important to use a high-quality 7 -ohm

Chapter 7: Telecom Connections

cable which will have more consistent shielding and conduction. The maximum length of each cable shall

be 440 meters for E3 or 300 meters for T3/DS3, but the acceptable cable lengths of equipment attached to

the converter must be met as well. For lengths over 13 meters, testing in field should be used to determine

whether bit error rates are acceptable. Long cable lengths also require careful selection of cable type and

attention to sources of external noise.

Third-party fiber to copper media converters can be used with the E3Switch converter to implement fiber-

optic DS3/E3 links; however, refer to the interoperability section of this document for vendors to avoid.

Chapter 8: LAN Connections and Performance

LAN Ports

Each LAN port implements the following features to maximize LAN compatibility and link utilization and

minimize packet loss:

·Autosense/Autoconfiguration/Autonegotiation with the attached LAN.

·100Mbit/sec or 1000Mbit/s.

·Full-duplex LAN connection.

·Data buffering.

·Upstream pause-frame flow-control messaging.

·Quality of service high-priority queuing in certain firmware.

·16 0-byte packet acceptance (13 0 for mgmt and 9600 for jumbo).

These features and their ramifications are discussed below in more detail.

Autonegotiation

he network equipment attached to the LAN port of the converter should be set for autonegotiation

mode in order to allow the converter to negotiate a 100Mbit full-duplex connection.