Extreme Networks WM-4T1i WAN User manual

Extreme Networks, Inc.
3585 Monroe Street
Santa Clara, California 95051
[phone]
http://www.extremenetworks.com
WM-4T1i Module
Installation and User
Guide
Published: June 2001
Part number: 100095-00 Rev. 01

ii
©2001 Extreme Networks, Inc. All rights reserved. Extreme Networks and BlackDiamond are
registered trademarks of Extreme Networks, Inc. in the United States and certain other jurisdictions.
ExtremeWare, ExtremeWare Vista, ExtremeWorks, ExtremeAssist, ExtremeAssist1, ExtremeAssist2,
PartnerAssist, Extreme Standby Router Protocol, ESRP, SmartTraps, Alpine, Summit, Summit1,
Summit4, Summit4/FX, Summit7i, Summit24, Summit48, Summit Virtual Chassis, SummitLink,
SummitGbX, SummitRPS, and the Extreme Networks logo are trademarks of Extreme Networks, Inc.,
which may be registered or pending registration in certain jurisdictions. The Extreme Turbodrive logo
is a service mark of Extreme Networks, which may be registered or pending registration in certain
jurisdictions. Specifications are subject to change without notice.
All other registered trademarks, trademarks, and service marks are property of their respective owners.

WM-4T1i Installation and User Guide iii
Contents
Preface
Introduction v
Conventions vi
Related Publications vii
1 Installing the WM-4T1i Module
Overview 1-1
Installing the WM-4T1i Module 1-2
Ports and Connectors 1-3
WM-4T1i Module LEDs 1-3
Installing the WM-4T1i Module Software 1-5
2 Configuring the T1 Physical Link
Overview 2-1
Configuring T1 Physical link 2-1
Alarms 2-2
Cable length 2-2
Clock Source 2-3
Facility Data Link 2-3
Framing 2-4
Inband Loopback Detection 2-4
Linecoding 2-4

iv WM-4T1i Installation and User Guide
Yellow Alarms 2-5
T1 Port Configuration Commands 2-5
Monitoring T1 Physical Link 2-6
Loopback 2-6
Near-end Loopback Modes 2-7
Far-End Loopback Modes 2-8
Enabling Loopback Mode 2-10
Disabling Loopback Mode 2-10
T1 Port Monitoring Commands 2-10
3 Configuring PPP and MLPPP
Overview 3-1
Multilink PPP and Multilink Groups 3-2
Configuring a PPP/MLPPP Link 3-3
Authentication 3-3
PPP Link Username 3-3
PPP User Accounts 3-4
Encapsulation 3-4
PPP/MLPPP Configuration Commands 3-5
Monitoring PPP/MLPPP Links 3-6
PPP/MLPPP Configuration Examples 3-6
Configuring a Bridged PPP/MLPPP Link Example 3-6
Configuring a Routed PPP/MLPPP Link Example 3-7
Index
Index of Commands

WM-4T1i Module Installation and User Guide v
Preface
This Preface provides an overview of this guide, describes guide conventions, and lists
other publications that may be useful.
Introduction
This guide provides the required information to install the WM-4T1i module in an
Alpine 3800 series switch from Extreme Networks and perform the initial module
configuration tasks.
This guide is intended for use by network administrators who are responsible for
installing and setting up network equipment. It assumes a basic working knowledge of:
•Local area networks (LANs).
•Ethernet concepts.
•Ethernet switching and bridging concepts.
•Routing concepts.
•Internet Protocol (IP) concepts.
•Routing Information Protocol (RIP) and Open Shortest Path First (OSPF).
•Simple Network Management Protocol (SNMP).
If the information in the release notes shipped with your module differs from the
information in this guide, follow the release notes.

vi WM-4T1i Module Installation and User Guide
Conventions
Table 1 and Table 2 list conventions that are used throughout this guide.
Table 1: Notice Icons
Icon Notice Type Alerts you to...
Note Important features or instructions.
Caution Risk of personal injury, system damage, or loss of data.
Warning Risk of severe personal injury.
Table 2: Text Conventions
Convention Description
Screen displays This typeface indicates command syntax, or represents information
as it appears on the screen.
Screen displays
bold
This typeface indicates how you would type a particular command.
The words “enter”
and “type” When you see the word “enter” in this guide, you must type something, and then press the Return or Enter key. Do not press the
Return or Enter key when an instruction simply says “type.”
[Key] names Key names are written with brackets, such as [Return] or [Esc].
If you must press two or more keys simultaneously, the key names
are linked with a plus sign (+). Example:
Press [Ctrl]+[Alt]+[Del].
Words in italicized type Italics emphasize a point or denote new terms at the place where
they are defined in the text.

WM-4T1i Module Installation and User Guide vii
Related Publications
Related Publications
The publications related to this one are:
•ExtremeWare™release notes
•ExtremeWare Software User Guide
•Alpine 3800 Series Switch Hardware Installation Guide
•Alpine Module Installation Note
Documentation for Extreme Networks products is available on the World Wide Web at
the following location:
http://www.extremenetworks.com/

viii WM-4T1i Module Installation and User Guide

WM-4T1i Module Installation and User Guide 1-1
1Installing the WM-4T1i Module
This chapter covers the following topics:
•Installing the WM-4T1i Module on page 1-2
•Ports and Connectors on page 1-3
•WM-4T1i Module LEDs on page 1-3
•Installing the WM-4T1i Module Software on page 1-5
Overview
The Extreme Networks WM-4T1i module is an four-port T1 module that can be
configured to use Multilink PPP to aggregate Ethernet traffic across multiple T1
physical links. The module has two 10/100 Mbps Ethernet ports.
The WM-4T1i module also has six internal loopback ports. The Alpine 3800 switch
modules have hardware queues associated with the output of each port for QoS (rate
shaping and priority queueing). To implement ingress QoS, you needed to use the
hardware queues associated with a second port as a loopback port for ingress QoS

1-2 WM-4T1i Module Installation and User Guide
Installing the WM-4T1i Module
Installing the WM-4T1i Module
All Alpine ™3800 series switch module cards (SMMi modules and I/O modules) are
hot-swappable. You do not need to power off the system to remove or insert a module
card.
Caution: Service to Alpine modules should be performed by trained service
personnel only. Before installing or removing any components of the system, or
before carrying out any maintenance procedures, read the safety information
provided in Appendix A of the Alpine Hardware Installation Guide.
Warning: You must install blank panels in empty slots to ensure adequate system
cooling.
To remove and replace a module card, follow these steps:
1Prior to removing/installing a module card into the Alpine 3804 or Alpine 3808
chassis, put on the ESD wrist strap that is provided with the chassis, and connect the
metal end to the ground receptacle located on the top-right corner of the Alpine
front panel.
2Loosen the module card by unscrewing the screws using a #2 Phillips-head
screwdriver.
3Rotate the ejector/injector handles to disengage the module card from the backplane.
Note: Blank panels do not have ejector/injector handles, because they do not
engage the backplane. They are secured entirely by the retaining screws. In
addition, the retaining screws are not captive.
4Slide the module card out of the chassis.
5Slide the new module card into the appropriate slot of the chassis (SMMi modules
into the orange slot, I/O modules into Slots 1 through 4 on the Alpine 3804, or Slots
1 through 8 on the Alpine 3808), until it is fully seated in the backplane.
Caution: Ensure that the sheet metal of the module, and not the PCB board,
engages the card cage runners.
As the module begins to seat in the chassis, the ejector/injector handles will begin to
close.
6To secure the module in the chassis, close the ejector/injector handles by pushing
them toward the center of the module card, and tighten the screws using a #2
Phillips-head screwdriver.

WM-4T1i Module Installation and User Guide 1-3
Ports and Connectors
Note: Tighten the screws before inserting additional modules. If you insert
additional modules before tightening the screws, you might unseat modules
that you have not secured.
Caution: You can only install I/O modules in the slots labeled Slot 1 through
Slot 4 on the Alpine 3804, or Slot 1 through Slot 8 on the Alpine 3808. Forceful
insertion can damage the I/O module and the connector pins on the backplane.
Ports and Connectors
The WM-4T1i module is show in Figure 1-1.
Figure 1-1: WM-4T1i Module
The WM-4T1i module has four T1 ports and two 10/100 Ethernet ports. The WM-4T1i
also has six internal loopback ports. Internal loopback ports allow you to configure
bi-directional rate-limiting without tying up any of the external ports for ingress rate
shaping. Internal loopback ports are marked with the notation “iL”when displayed on
the command line or with ExtremeWare Vista Web access.
WM-4T1i Module LEDs
The WM-4T1i module LEDs are shown in Figure 1-1.
38_WM4T1i
Module status
LEDs T1 ports 10/100 Mbps ports

1-4 WM-4T1i Module Installation and User Guide
Installing the WM-4T1i Module
Figure 1-2: WM-4T1i LEDs
Table 1-1 describes the LED behavior on the WM-4T1i module.
Table 1-1: WM-4T1i Module LEDs
LED Color Indicates
Status Off No power
Amber Module seated in chassis
Green Module powered up
Diag Green (blinking) Power-on Self Test (POST) is running
Off Normal operation
T1 port (1-4) Amber Near-end fault detected (for example, no cable)
Rapidly blinking
amber Far-end fault detected
Slowly blinking
amber Physical link present, but no higher-layer link (port misconfigured or disabled)
Green Physical link present, higher-layer link established,
no traffic
Alternating green
and amber Physical link present, higher-layer link established, traffic present
Green (blinking) Loopback testing mode
10/100 port
(5,6) Off No link present
Green Link present
Alternating green
and amber Traffic present

WM-4T1i Module Installation and User Guide 1-5
Installing the WM-4T1i Module Software
The slowly blinking LEDs cycle once per second. The rapidly blinking LEDs cycle twice
a second.
Installing the WM-4T1i Module Software
Once the WM-4T1i module is installed in the chassis, you must download an image file
to the module.
The image file contains the executable code that runs on the module. As new versions
of the image are released, you should upgrade the software running on your module.
The image is downloaded from either a Trivial File Transfer Protocol (TFTP) server on
the network or from a PC connected to the serial port using the XMODEM protocol.
Downloading a new image involves the following steps:
•Load the new image onto a TFTP server on your network (if you will be using
TFTP).
•Load a new image onto a PC (if you will be using XMODEM).
•Download the new image to the module using the command
download image slot <slot> [<ipaddress> | <hostname>] <filename>
{primary | secondary}
where the following is true:
slot —Is the slot in which the WM-4T1i module is installed.
ipaddress —Is the IP address of the TFTP server.
hostname —Is the hostname of the TFTP server. (You must enable DNS to use this
option. See the ExtremeWare Software User Guide for more information.)
filename —Is the filename of the new image.
primary —Indicates the primary image.
secondary —Indicates the secondary image.
The module can store up to two images; a primary and a secondary. When you
download a new image, you must select into which image space (primary or secondary)
the new image should be placed. If not indicated, the primary image space is used.
You can select which image the switch will load on the next reboot by using the
following command:

1-6 WM-4T1i Module Installation and User Guide
Installing the WM-4T1i Module
use image [primary | secondary]

WM-4T1i Module Installation and User Guide 2-1
2Configuring the T1 Physical Link
This chapter covers the following topics:
•Configuring T1 Physical link on page 2-1
•Monitoring T1 Physical Link on page 2-6
Overview
T1 is a mature technology originally developed for voice telephone transmission. It was
used to aggregate a number of voice lines into a single connection to the telephone
network. Today T1 is also widely used to transmit digital data using widely available
equipment and established wiring commonly available in diverse locations.
Configuring T1 Physical link
There are a number of parameters that can be configured for a T1 link. If you have
control of both sides of the link, then the default configuration is probably the best
choice. If you must connect to a line controlled by another organization, you will need
to configure the line to correspond with the settings at the other end. You can specify
the following parameters:
•Alarms
•Cable length

2-2 WM-4T1i Module Installation and User Guide
Configuring the T1 Physical Link
•Clock Source
•Facility Data Link
•Framing
•Inband Loopback Detection
•Linecoding
•Yellow Alarms
Alarms
The T1 standard, ANSI T1.403, Bellcore TR-54016 and others, defines red, yellow, and
blue alarms.
A red alarm occurs when the T1 signal is lost or an out of frame error occurs. An out of
frame error can be caused when the framing type configured for the local interface does
not match the framing type of the incoming T1 signal or when the incoming signal does
not contain a T1 framing pattern.
A yellow alarm is also called a Remote Alarm Indication (RAI). When the remote end of
a link does not receive a signal, it will transmit a yellow alarm signal back to the local
end.
A blue alarm is also called an Alarm Indication Signal (AIS). A blue alarm indicates that
a device somewhere upstream has experienced a loss of signal.
The default value is on. To configure whether alarms are generated and detected, use
the following command:
config ports <portlist> t1 alarms [on | off]
Yellow alarms can be configured when T1 alarms are enabled. See “Yellow Alarms”on
page 2-5 for more details on the following command:
config ports <portlist> t1 yellow [detection | generation | both | off]
Cable length
Longer cable lengths cause greater loss for the T1 signal, so the transmitter hardware
must transmit at a higher level to transmit data successfully. However, too high a signal
level can cause crosstalk from one cable to another. The config ports t1

WM-4T1i Module Installation and User Guide 2-3
Configuring T1 Physical link
cablelength command allows you to control the transmitter signal level for your
conditions. Typically, your service provider will suggest the correct level.
For short haul connections (less then 700 feet) the typical equipment uses less sensitive
receivers. The transmitter level is usually set by selecting a cable length in feet, from the
following values: 133, 266, 399, 533 or 655. Choose the next higher value if your cable
length does not match one of the values. For example, choose 133 for a 50 foot cable
and 533 for a 450 foot cable. The default value is 133, which corresponds to cables in the
range of 0-133 feet.
For longer distances (up to 6000 feet) the typical equipment uses more sensitive
receivers, and crosstalk is more likely to occur. Under these conditions, the transmitter
level is set by selecting a transmitter attenuation level in dB from the following values:
-22.5, -15, -7.5, or 0.
From lowest to highest transmitter level, use the following values for the config port
t1 cablelength command: -22.5 db, -15 db, -7.5 db, 0 db, 133 feet, 266 feet, 399 feet,
533 feet, and 655 feet.
To configure the cable length, use one of the following commands:
config ports <portlist> t1 cablelength [0 | -7.5 | -15 | -22.5] db
config ports <portlist> t1 cablelength [133 | 266 | 399 | 533 | 655]
feet
CLOCK SOURCE
A clock is used to synchronize data transmission on the line. Generally, one end of the
T1 link provides the master clock, and the other end of the link recovers the clock from
the signal on the line. By default the clock source is derived from the line. If needed, an
internal clock is available. To configure the clock source, use the following command:
config ports <portlist> t1 clocksource [internal | line]
Note: If the clock source is configured as “line”, but the clock cannot be
recovered from the signal on the line, the hardware will use the internal clock
instead.
Facility Data Link
Facility data link (FDL) uses twelve bits in the ESF frame to signal information about
line and connection status. Since FDL is only meaningful for ESF framing, FDL settings

2-4 WM-4T1i Module Installation and User Guide
Configuring the T1 Physical Link
are ignored when a port is configured for SF framing. See “Framing”for information on
configuring framing.
The two standards supported for FDL are ATT, described by the ATT 54016
specification, and ANSI, described by the T1.403 standard. The default value is off. To
configure FDL, use the following command:
config ports <portlist> t1 fdl [off | att | ansi]
Framing
Framing is used to synchronize data transmission on the T1 line. Framing allows the
hardware to determine when each packet starts and ends. The two choices for framing
are Super Frame (SF), also known as D4, and Extended Super Frame (ESF). The ESF
scheme is a newer standard and is enabled by default. To choose the framing scheme,
use the following command:
config ports <portlist> t1 framing [esf | sf]
If you choose to use SF framing, you should disable yellow alarm detection for the T1
line. SF framing may generate false yellow alarms. See “Yellow Alarms”on page 2-5 for
more details.
Inband Loopback Detection
When inband loopback detection is enabled, a specific sequence of data in the signal
payload from the remote end of the T1 link will cause the local end to enter network
line loopback mode and send any received signal back to the remote end. Inband
loopback detection is only possible if the FDL standard is configured as ATT. See
“Facility Data Link”on page 2-3 for more details. By default, inband loopback detection
is off. See “Loopback”on page 2-6 for more information about loopback modes. To
configure inband loopback detection, use the following command:
config ports <portlist> t1 lbdetect [off | inband]
Linecoding
Linecoding is the convention used to encode signals for transmission over the T1 line.
You can choose from two linecoding standards, bipolar eight zero suppression (B8ZS) or
alternate mark inversion (AMI). The default value is B8ZS. To configure linecoding, use
the following command:
config ports <portlist> t1 linecoding [b8zs | ami]

WM-4T1i Module Installation and User Guide 2-5
Configuring T1 Physical link
Yellow Alarms
A yellow alarm occurs on a device when its signal is not received at the remote end. It
is also called a Remote Alarm Indication (RAI). You can disable detection and
generation of yellow alarms for a T1 port. When SF framing is used, yellow alarm
detection and generation should be set to off, because detection of yellow alarms is not
reliable when data traffic is transmitted with SF framing (data traffic often contains bit
combinations that do not occur for encoded voice traffic). The default value for yellow
alarm generation and detection is both. To configure yellow alarms, use the following
command:
config ports <portlist> t1 yellow [detection | generation | both | off]
T1 Port Configuration Commands
Table 2-1 describes the commands used to configure a T1 port.
Table 2-1: T1 Port Configuration Commands
Command Description
config ports <portlist> t1 alarms [on | off] Enables and disables alarms. The default
setting is on.
config ports <portlist> t1 cablelength [
[133 | 266 | 399 | 533 | 655] feet
| [0 | -7.5 | -15 | -22.5] dB]
Specifies the cablelength attached to the T1
port. The default is 0 dB.
config ports <portlist> t1 clock source [internal
| line] Specifies the clock source used for transmission. The default setting is line.
config ports <portlist> t1 fdl [off | att | ansi] Specifies the facilities data link (FDL) format for
the port. You cannot use FDL with SF framing.
config ports <portlist> t1 framing [esf | sf] Specifies the framing type. The default setting
is esf, Extended Super Frame (ESF). If sf is
chosen, Super Frame (SF), set yellow alarm
detection to off, since a yellow alarm can be
incorrectly detected with SF framing.
config ports <portlist> t1 lbdetect [off | inband] Enables and disables the port to respond to
loopback requests from the remote end. The
default setting is off.
config ports <portlist> t1 linecode [b8zs | ami] Sets the linecoding. The default setting is b8zs.
config ports <portlist> t1 yellow [detection |
generation | both | off] Enable and disable yellow alarm detection and generation.

2-6 WM-4T1i Module Installation and User Guide
Configuring the T1 Physical Link
Monitoring T1 Physical Link
T1 devices have a built-in facility designed for troubleshooting the physical link, called
loopback. The T1 link can also be monitored using show commands to display the
current configuration of the link, any alarms on the link, link statistics, and link errors.
Loopback
The T1 device can be set up to loopback, that is, return a transmitted signal back to the
sender so it can be compared with the original. There are several different types of
loopback available to test different parts of the device and the line, specified in the T1
standards.
Figure 2-1: Normal operation of T1 link
During normal operation of a T1 link, as the local data stream enters the framer, the
appropriate framing bits are inserted into the data, and the framed signal is transmitted
to the remote end. At the remote end, the process is reversed as the framing bits are
discarded and the data stream is passed to the remote system.
Loopback can be enabled on the near-end or the far-end of the link. The near-end
loopback modes are controlled directly by the hardware on the near-end. Far-end
loopback modes require the cooperation of the far-end hardware. A message is sent to
the far-end to cause it to enter a far-end loopback mode. When loopback is enabled on a
T1 port, the green port LED will blink.
XM_010
Local T1 Port Remote T1 Port
Framer
Data in
Data out
Data out
Data in
Framer
Data with framing