Cisco 1700 series User manual

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Copyright © 2002. Cisco Systems, Inc. All rights reserved.
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Configuring an ADSL WAN Interface Card on
Cisco 1700 Series Routers
This document describes asymmetric digital subscriber line (ADSL) one-port wide area network (WAN)
interface cards (WICs). These cards provide ADSL high-speed digital data transfer between a single
customer premises equipment (CPE) subscriber and a central office.
ADSL WICs are available in three variations: ADSL over POTS (WIC-1ADSL), ADSL over POTS with
Dying Gasp support (WIC-1ADSL-DG), and ADSL over ISDN with DyingGasp support
(WIC-1ADSL-I-DG). The ADSL over POTS WICs are commonly used to provide ADSL services over
ordinary telephone lines. The ADSL over ISDN WIC is used to provide ADSL services in those areas of
the world which have extensive ISDN backbones already in place.
This document contains the following sections:
•Feature Overview, page 2
•Related Documents, page 3
•FCC Notice, page 3
•Safety Warnings, page 4
•Connecting an ADSL WIC to the Network, page 6
•Configuring the ADSL Interface, page 7
•Using POTS Splitters and Microfilters, page 13
•Configuring Quality of Service Parameters, page 17
•Configuring the SCC Clock Rate, page 28
•Configuring FRF.5 and FRF.8 Internetworking Functions, page 29
•Obtaining Documentation, page 30
•Obtaining Technical Assistance, page 31

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Feature Overview
Feature Overview
Figure 1 shows a data network with the card. Figure 2 shows a voice network with the card.
Figure 1 ADSL WIC in a Cisco 1700 Series Router Data Network
Figure 2 ADSL WIC in a Cisco 1700 Series Router Voice Network
On Cisco 1700 series routers, an ADSL WIC fits into a Cisco 1700 series router chassis. The card
supports data and voice networks through the asynchronous transfer mode (ATM) protocol with the
AAL5 format. ATM quality of service (QoS) for permanent virtual circuits (PVCs) is also supported.
Figure 3, Figure 4, and Figure 5 show the various ADSL WICs.
Figure 3 ADSL over POTS WIC
ADSL WIC
AAL5
ADSL
DSLAM
41852
ADSL WIC
AAL5
ADSL
DSLAM
Analog phones
41851
SEE MANUAL
BEFORE INSTALLATION
WIC
1ADSL
38913
CD LP OK
ADSL

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Related Documents
Figure 4 ADSL over POTS with Dying Gasp WIC
Figure 5 ADSL over ISDN with Dying Gasp WIC
Memory Requirements
The memory requirements for running the full-featured Cisco 1700 router encryption images with the
ADSL WICs are as follows:
•16 MB of Flash memory
•64 MB of dynamic RAM (DRAM)
Related Documents
The following documents provide additional information about installing and configuring ADSL WICs
and configuring the router software:
•Cisco WAN Interface Cards Hardware Installation Guide—provides installation information on the
ADSL WAN interface card.
•Regulatory Compliance and Safety Information document—provides safety warnings and
compliance information for your router.
•Cisco 827 Routers Software Configuration Guide—provides router configurations for ATM data and
voice networks for the Cisco 827-4V router. These configurations will also work for the Cisco 1720,
1721, 1751, and 1760 routers, except for the dialer interface.
•Cisco IOS configuration guides and command references—provides IOS commands and
configurations for your router.
The following document provides additional information about configuring QoS features and Frame
Relay Forum (FRF) internetworking functions on ADSL WICs.
•Enhanced Voice and QoS for ADSL and G.SHDSL on Cisco 1700 Series, Cisco 2600 Series, and
Cisco 3600 Series Routers
FCC Notice
The following FCC Notice applies to the Cisco 1700 series ADSL WIC:
WIC-1ADSL complies with FCC part 68 FCC ID:5B1USA-42011-DL-N
WIC
1ADSL DG
ADSL
SEE MANUAL
BEFORE INSTALLATION
CD LP OK
88862
WIC
1ADSL IDG
ADSL
SEE MANUAL
BEFORE INSTALLATION
CD LP OK
88863

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Safety Warnings
Safety Warnings
Safety warnings appear throughout this publication in procedures that can harm you if they are
performed incorrectly. A warning symbol precedes each warning statement.
Warning Conventions
Power Supply Warnings
The following warnings apply when you are installing a card or working with the power supply:
Warning Read the installation instructions before you connect the system to its power source.
Warning Only trained and qualified personnel should be allowed to install or replace this equipment.
Warning Ultimate disposal of this product should be handled according to all national laws and regulations.
Warning When installing or replacing the unit, the ground connection must always be made first and
disconnected last.
Warning This equipment must be grounded. Never defeat the ground conductor or operate the equipment in the
absence of a suitable installed ground conductor. Contact the appropriate electrical inspection
authority or an electrician if you are uncertain that suitable grounding is available.
Warning Use copper conductors only.
Warning Blank faceplates and cover panels serve three important functions: they prevent exposure to
hazardous voltages and currents inside the chassis; they contain electromagnetic interference (EMI)
that might disrupt other equipment; and they direct the flow of cooling air through the chassis. Do not
operate the system unless all cards, faceplates, front covers, and rear covers are in place.
Warning This warning symbol means danger. You are in a situation that could cause bodily injury. Before you
work on any equipment, be aware of the hazards involved with electrical circuitry and be familiar
with standard practices for preventing accidents. To see translations of the warnings that appear in
this publication, refer to the Regulatory Compliance and Safety Information document that
accompanied this device.

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Safety Warnings
The following warning applies when this product is used in Australia.
Warning This equipment must be installed and maintained by service personnel as defined by AS/NZS 3260.
Incorrectly connecting this equipment to a general purpose outlet could be hazardous. The
telecommunications lines must be disconnected 1) before unplugging the main power connector or 2)
while the housing is open, or both.
Electrical Warnings
The following warnings apply when you are working with electricity:
Warning Before working on equipment that is connected to power lines, remove jewelry (including rings,
necklaces, and watches). Metal objects will heat up when connected to power and ground and can
cause serious burns or weld the metal object to the terminals.
Warning Before opening the unit, disconnect the telephone-network cables to avoid contact with
telephone-network voltages.
Warning Do not work on the system or connect or disconnect cables during periods of lightning activity.
Warning Do not use this product near water; for example, near a bath tub, wash bowl, kitchen sink or laundry
tub, in a wet basement, or near a swimming pool.
Warning Never install telephone jacks in wet locations unless the jack is specifically designed for wet
locations.
Warning Never touch uninsulated telephone wires or terminals unless the telphone line has been
disconnected at the network interface.
Warning Avoid using a telephone (other than a cordless type) during an electrical storm. There may be a remote
risk of electric shock from lightning.
Warning To report a gas leak, do not use a telephone in the vicinity of the leak.

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Connecting an ADSL WIC to the Network
Warning Do not touch the power supply when the power cord is connected. For systems with a power switch,
line voltages are present within the power supply even when the power switch is OFF and the power
cord is connected. For systems without a power switch, line voltages are present within the power
supply when the power cord is connected.
Follow these guidelines when working on equipment powered by electricity:
•Locate the emergency power-off switch in the room in which you are working. Then, if an electrical
accident occurs, you can quickly turn off the power.
•Before working on the router, turn off power to the router, and unplug the power cord.
•Disconnect all power before doing the following:
– Installing or removing a router chassis
– Working near power supplies
•Do not work alone if potentially hazardous conditions exist.
•Never assume that power is disconnected from a circuit. Always check.
•Look carefully for possible hazards in your work area, such as moist floors, ungrounded power
extension cables, and missing safety grounds.
If an electrical accident occurs, proceed as follows:
•Use caution; do not become a victim yourself.
•Turn off power to the router.
•If possible, send another person to get medical aid. Otherwise, determine the condition of the victim,
and then call for help.
•Determine whether the victim needs rescue breathing or external cardiac compressions; then take
appropriate action.
Preventing Electrostatic Discharge Damage
Electrostatic discharge (ESD) can damage equipment and impair electrical circuitry. It can occur when
printed circuit cards are improperly handled and can result in complete or intermittent failures. Always
follow ESD prevention procedures when removing and replacing cards. Ensure that the router chassis is
electrically connected to earth/ground. Wear an ESD-preventive wrist strap, ensuring that it makes good
skin contact. Connect the clip to an unpainted surface of the chassis frame to safely channel unwanted
ESD voltages to ground. To guard against ESD damage and shocks, the wrist strap and cord must be used
properly. If no wrist strap is available, ground yourself by touching the metal part of the chassis.
Caution For safety, periodically check the resistance value of the antistatic strap, which should be between 1
and 10 megohms (Mohms).
Connecting an ADSL WIC to the Network
For this connection, use a standard lavender RJ-11 cable.

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Configuring the ADSL Interface
Note If you are connecting a Cisco 1700 series router with an ADSL WIC to an RJ-11 wall jack that has
the ADSL pair wired for pins 2 and 5, you must use the lavender crossover cable with the blue stripe.
The crossover cable is orderable as a spare.
The following steps tell how to connect the card, using the standard lavender RJ-11 cable; the steps also
apply to the lavender crossover cable with the blue stripe.
Step 1 Confirm that router power is still turned off.
Step 2 Connect one end of the cable (RJ-11) to the ADSL port on the card.
Step 3 Connect the other end of the cable to the wall jack (RJ-11) at your site, as shown in Figure 6.
Figure 6 Connecting an ADSL WIC to a Wall Jack
Step 4 Turn on power to the router.
The following warning applies to routers that use a DC power supply:
Step 5 To connect the card to the network, you must configure the ADSL card in the router to the no shutdown
state. Enter the no shut command in the router configuration. Verify that the CD LED comes on,
indicating that the card is connected to the network.
Configuring the ADSL Interface
Whenever you install a new WIC, or if you want to change the configuration of an existing interface, you
must configure the interface. If you replace a card that was already configured, the router recognizes it
and brings up the interface in the existing configuration.
Before you configure an interface, have the following information available:
•Protocols you plan to route on the new interface
•IP addresses, subnet masks, network numbers, zones, virtual path identifier/virtual channel
identifier (VPI/VCI) number(s), or other information related to the routing protocol
RJ-11
wall jack
41200
SEE MANUAL
BEFORE
INSTALLATION
OK CD LP
ADSL
RJ-11 cable
ADSL port
(RJ-11)

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Configuring the ADSL Interface
Timesaver Obtain this information from your system administrator or network plan before you begin router
configuration.
You can configure the new interface and other router parameters by using any of the following methods:
•Configuration Mode (manual configuration)—recommended if you are familiar with IOS
commands. Enter the commands at the prompt.
•AutoInstall (automatic installation)—recommended if another router running IOS software is
installed on the network. This configuration method must be coordinated in advance by someone
with experience using IOS software, such as the network administrator.
•System Configuration Dialog (Setup facility)—recommended if you are not familiar with IOS
commands. You are prompted for each response.
These procedures are explained in the following sections. To change the settings shown in the examples,
and for further information, refer to the IOS configuration guides and command references. If you have
questions or need help, see the section “Obtaining Technical Assistance” later in this document.
Default Commands
The IOS software provides the following default configurations for ADSL-specific parameters.
The following default command sets the ADSL operating mode:
dsl operating-mode auto
The following command sets the ATM virtual circuit-per-virtual path (vc-per-vp) configuration for the
router:
atm vc-per-vp 256
Defaults for WIC-1ADSL-I-DG
For the WIC-1ADSL-I-DG, the default command operating-mode auto sets the carrier tone range from
33 to 56 to meet the requirements of the Deutsche Telekom U-R2 specification.
Alternately, to set the carrier tone range from 29 to 48, use the command
dsl operating-mode auto tone low
This command, dsl operating-mode auto tone low, is not available on the WIC-1ADSL or
WIC-1ADSL-DG.
Configuration Mode
You can configure the interfaces on your ADSL WIC manually by entering IOS commands on the
command line. This method, called configuration mode, provides the greatest power and flexibility.
For further information about these commands, refer to the IOS configuration guides and command
references.

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Configuring the ADSL Interface
Before you begin, disconnect all WAN cables from the router to keep it from running the AutoInstall
process. The router tries to run AutoInstall whenever you power it on if there is a WAN connection on
both ends and the router does not have a valid configuration file stored in NVRAM (for instance, when
you add a new interface). It can take several minutes for the router to determine that AutoInstall is not
connected to a remote Transmission Control Protocol/Internet Protocol (TCP/IP) host.
To enter configuration mode, follow this procedure:
Step 1 Connect a console to the router. If you need instructions for connecting a console, refer to the
installation chapter of your router installation and configuration guide. Power up the router.
Step 2 If the current configuration is no longer valid, after about one minute you see the following prompt:
Would you like to enter the initial dialog? [yes]:
Enter no. You now enter the normal operating mode of the router.
Note If the current configuration is valid, you enter the normal operating mode automatically.
Step 3 After a few seconds, you see the user EXEC prompt. Type enable and the password to enter enable
mode:
Router> enable
Password:
Configuration changes can be made only in enable mode. The prompt changes to the privileged EXEC
(enable) prompt (Router#):
Router#
Step 4 Enter the config terminal command to enter configuration mode:
Router# config terminal
Router(config)#
The router enters global configuration mode, indicated by the Router(config)# prompt.
Step 5 If you have not configured the router before or want to change the configuration, you can configure
global parameters, passwords, network management, and routing protocols. In this example, IP routing,
AppleTalk routing, and Internetwork Packet Exchange (IPX) routing are all enabled:
Router(config)# ip routing
Router(config)# appletalk routing
Router(config)# ipx routing
For complete information about global configuration commands, refer to the IOS configuration guides
and command references.
Step 6 Select the ADSL interface to configure:
Router(config)# interface atm 0
Router(config-if)#
The prompt changes again to show that you are in interface configuration mode.
Note For the Cisco 1751 and 1760 routers, enter the command as interface atm slot/port. For
example, interface atm 0/0.
Step 7 Select the ADSL operating mode:

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Configuring the ADSL Interface
Router (config-if) dsl operating-mode mode
Caution This command is for testing or lab environments only. Using a mode other auto for the DSL operating
mode can lead to unpredictable behavior on the ADSL line.
Step 8 Configure routing protocols on the interface. (You must have previously enabled these protocols as part
of global configuration.) In this example, IP, AppleTalk, and IPX are being configured on the ADSL
interface:
Router(config-if)# ip address 1.10.16.16 255.255.0.0
Router(config-if)# appletalk static cable-range 5-5
Router(config-if)# appletalk zone ZZ
Router(config-if)# ipx network B004
Step 9 Configure a PVC on the interface. (You must have the VPI/VCI number from the service provider
before you configure this.)
Router (config-if)# pvc 0/33
Router (config-if-atm-vc)# protocol ip 1.10.16.16 broadcast
Router (config-if-atm-vc)# vbr-rt 160 160 1
Router (config-if-atm-vc)# encapsulation aal5snap
Step 10 To configure another interface, enter the exit command to return to the Router(config)# prompt.
Repeat Step 6 through Step 9 of this procedure to configure the next interface.
Step 11 When you finish configuring interfaces, exit configuration mode. Return to the enable prompt by
pressing Ctrl-Z. To see the current operating configuration, including any changes you just made, enter
the show running-config command:
Router# show running-config
To see the configuration currently stored in NVRAM, enter the show startup-config command:
Router# show startup-config
Step 12 The results of the show running-config and show startup-config commands differ if you have made
changes to the configuration but have not yet written them to NVRAM. To write your changes to
NVRAM and make them permanent, enter the copy running-config startup-config command:
Router# copy running-config startup-config
Building configuration. . .
[OK]
Router#
The router is now configured to boot in the new configuration.
AutoInstall
The AutoInstall process is designed to configure the router automatically after it connects to your WAN.
For AutoInstall to work properly, a TCP/IP host on your network must be configured to provide the
configuration files. The TCP/IP host can reside anywhere on the network if the following two conditions
are met:
•The host must be on the remote side of the router’s synchronous serial connection to the WAN.
•User Datagram Protocol (UDP) broadcasts to and from the router and the TCP/IP host must be
enabled.

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Configuring the ADSL Interface
This functionality is coordinated by your system administrator at the TCP/IP host site. You should not
try to use AutoInstall unless the required files are installed on the TCP/IP host.
Follow this procedure to prepare your router for the AutoInstall process:
Step 1 Connect the router to the WAN.
Step 2 Turn on power to the router.
The router loads the operating system image from Flash memory. If the remote end of the WAN
connection is connected and properly configured, the AutoInstall process begins.
Step 3 If AutoInstall succeeds, you should write the configuration data to the router’s NVRAM. To do this,
enter the copy running-config startup-config command at the Router# prompt:
Router# copy running-config startup-config
Building configuration. . .
[OK]
Router#
Note This step saves the configuration settings that the AutoInstall process created. If you do not
do this, your new configuration will be lost the next time you boot the router.
System Configuration Dialog
You can configure the router manually, using the System Configuration dialog (also called the Setup
facility). Unlike configuration mode, the System Configuration dialog prompts you for each response.
Before you begin, disconnect all WAN cables from the router to keep it from trying to run the AutoInstall
process. The router tries to run AutoInstall whenever you power it on if there is a WAN connection on
both ends and the router does not have a configuration file stored in NVRAM. It can take several minutes
for the router to determine that AutoInstall is not connected to a remote TCP/IP host.
This section shows a sample configuration using the System Configuration dialog. You should enter
values appropriate for your router and network. To change the settings shown in the examples, and for
further information, refer to the IOS configuration guides and command references.
Many prompts in the System Configuration dialog include default answers, shown in square brackets
following the question. Enter your response, or press Return to accept the default answer.
You can request help at any time by entering a question mark (?) at the System Configuration dialog
prompt.
Follow this procedure to configure the router, using the System Configuration dialog:
Step 1 Connect a console to the router. If you need instructions for connecting a console, refer to your router
installation and configuration guide. Power up the router.
Step 2 If the current configuration is no longer valid, after about one minute you see the following prompt:
Would you like to enter the initial dialog? [yes]:
Press Return or enter yes to enter the System Configuration dialog.

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Configuring the ADSL Interface
Note You can enter the System Configuration dialog at any time from the enable prompt (Router#)
by entering the setup command.
Step 3 When the System Configuration dialog asks whether you want to view the current interface summary,
press Return or enter yes.
Step 4 If you have not configured the router before, or if you want to change the configuration, you should
now configure global parameters, passwords, network management, and routing protocols. Refer to the
procedures in the IOS configuration guides and command references. Press Return to accept the
default values.
Step 5 The System Configuration dialog prompts you to configure network interfaces. When you reach the
ATM interface, determine which protocols you want on the interface, and enter the appropriate
responses. (You must have previously enabled these protocols as part of the global configuration.)
Step 6 If your router has more than one LAN interface, repeat Step 5 to configure each LAN interface.
Step 7 The configuration you entered is displayed as a command script, and you are asked if you want to use
it. If you enter no, the information you just entered is discarded, and you can begin the configuration
again. If you enter yes, the configuration is saved in the startup configuration:
Use this configuration? [yes/no]: yes
Building configuration...
Use the enabled mode 'configure' command to modify this configuration.
Press RETURN to get started!
The configuration is saved. If you added an interface, the router reboots in the new configuration when
you press Return.
You can configure the router for ATM and ADSL parameters using the following scenarios:
•Replacing a bridge or modem with the ADSL card
•PPP over ATM with Network Address Translation (NAT)
•RFC 1483 encapsulation with NAT
•Integrated routing and bridging
•Concurrent routing and bridging
The scenario configurations above are identical to those for the Cisco 827-4V router. To configure these
scenarios on the Cisco 1720, 1721, 1751, and 1760 routers with the ADSL WIC, refer to the Cisco 827
Routers Software Configuration Guide.
You can also access the information online at the following location:
http://www.cisco.com/univercd/cc/td/doc/product/access/acs_fix/827/index.htm.
Example Configuration
The following example shows a Cisco 1751 router configured for bridging on the ATM interface with an
ADSL over POTS card:
Current configuration :
!
version 12.2

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Using POTS Splitters and Microfilters
no parser cache
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname 1751-uut1
!
interface ATM0/0
mtu 4000
ip address 1.0.0.1 255.0.0.0
atm vc-per-vp 256
no atm ilmi-keepalive
pvc 0/16 ilmi
pvc 88/88
encapsulation aal5snap
!
bundle-enable
dsl operating-mode auto
bridge-group 1
!
interface FastEthernet0/0
ip address 6.0.0.1 255.0.0.0
speed auto
half-duplex
bridge-group 1
no cdp enable
!
ip classless
no ip http server
!
bridge 1 protocol ieee
!
line con 0
line aux 0
line vty 0 4
login
!
end
Using POTS Splitters and Microfilters
POTS splitters and microfilters are used on telephone lines to ensure voice- and data-call quality. This
section describes splitters and microfilters and tells how and when to use them with the Cisco 1700 series
routers. POTS splitters result in the best data and voice performance when the router and the telephone
are used on the same telephone line.
POTS Splitters
A POTS splitter (also called a splitter) is installed on a telephone line that is connected to both data
(high-frequency) and voice (low-frequency) devices. The splitter routes the high-frequency and
low-frequency signals on the telephone line to the correct device. Signals intended for the router can
disrupt voice calls; signals intended for voice calls can affect router operation.
Most splitters must be installed by the telephone company; however, some splitters can be installed by
the customer. If you are not sure what type of splitter to use, contact your service provider.

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Using POTS Splitters and Microfilters
Figure 7 is an example of a type of POTS splitter that is installed at the customer premises by the
customer. Other types of POTS splitters are installed by the telephone company on an exterior wall of
the customer premises.
Figure 7 POTS Splitters
Microfilters
Microfilters are installed on telephones to improve voice-call quality when voice and data equipment are
using the same telephone line (twisted pair). You should use microfilters with the Cisco 1700 series
routers only when the two following conditions exist:
•The documentation for the telephone(s) you are using with the router states that microfilters should
be used with the phone.
•Poor telephone call quality can be resolved by installing a microfilter on the phone line.
Figure 8 shows one type of microfilter.
Figure 8 Microfilter
Common Splitter and Microfilter Configurations
This section describes the most common scenarios for using splitters and microfilters with the
Cisco 1700 series routers. The scenarios are listed from most common to least common.
To
To wall jac
k
41199
DATA VOICE
To wall jack
o phone
41201
WALL
PHONE

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Using POTS Splitters and Microfilters
Telephone Company-Installed Splitter
This scenario is described below and illustrated in Figure 9.
•The telephone company has provisioned a single copper pair to be used by both the telephone
(POTS) service and the router with an ADSL card, so a POTS splitter must be installed.
•The splitter is installed by the telephone company on the customer premises. This type of splitter is
also referred to as a network interface device (NID).
•The router and telephone are on separate lines (twisted pair) to the splitter.
•The router and telephone share the same telephone line (twisted pair) to the telephone company.
Figure 9 Telephone Company-Installed Splitter
Customer-Installed Splitter
This scenario is described below and illustrated in Figure 10.
•The telephone company has provisioned a single copper pair to be used by both the telephone
(POTS) service and the router with an ADSL card, so a POTS splitter must be installed.
•The splitter is installed by customer on the customer premises.
•Router and telephone are directly connected to the splitter, which is connected to the telephone line.
•Router and telephone share the same telephone line (twisted pair) to the telephone company.
•For optional telephones connected through the splitter, microfilters are optional. They should be
installed only if they improve telephone call quality.
•For telephones connected directly to the telephone line, microfilters are required.
Splitter (NID)
To telco
Cisco router
Optional
microfilters
39196
Actual wall of building

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Using POTS Splitters and Microfilters
Figure 10 Customer-Installed Splitter
Router and Telephone Using Separate Telephone Lines
This scenario is described below and illustrated in Figure 11.
•The telephone company has provisioned a single copper pair to be used exclusively by the router
with an ADSL card and a separate copper pair to be used exclusively by the telephone (POTS)
service; therefore, neither a POTS splitter nor a microfilter is needed.
•The microfilter is optional; it should be installed only if it improves telephone call quality.
Figure 11 No Splitter, Optional Microfilter
Splitter
To telco
Optional telephones,
if supported by your telco
Required microfilter
Actual wall of building
39275
Cisco router
Optional
microfilters
Optional microfilter
to telco (ADSL
or G.SHDSL)
Line 2
to telco (POTS)
Actual wall of building
39197
Cisco router

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Configuring Quality of Service Parameters
Configuring Quality of Service Parameters
This section discusses quality of service (QoS) parameters that can be configured for the 1700 series
platforms when using the ADSL WIC. The following features are included:
•Low Latency Queuing (Priority Queuing with Class-Based Weighted Fair Queuing)
•DiffServ
•Committed Access Rate
•Multilink PPP over ATM with Link Fragmentation and Interleaving
•Weighted Random Early Detection
•ATM per-VC Queuing and VC Bundling
•ATM Cell Loss Priority Bit Marking
•Compressed RTP
•Tunable Transmission Ring
•MLP Bundling
Low Latency Queuing (Priority Queuing with Class-Based Weighted Fair
Queuing)
Low latency queuing (LLQ) allows strict priority queuing (PQ) to class-based weighted fair queuing
(CBWFQ). This priority queuing allows delay-sensitive data such as voice packets to be de-queued and
sent before other packet traffic, reducing jitter in voice conversations. To configure LLQ, enter the
priority command under the CBWFQ configuration.
Configuration Example
The following example shows a Cisco 1751 router configured with LLQ.
hostname zorro
username ruby-1 password 7 36497A4872384A
!
class-map match-all VOIP
match ip dscp 32
class-map CRITICAL
match access-group 100
!
policy-map 1751_ADSL
class CRITICAL
priority 48
class VOIP
bandwidth 64
set ip precedence 6
!
interface Loopback1
ip address 10.0.0.10 255.255.255.252
!
interface ATM0/0
dsl operating-mode auto
no ip address
no atm ilmi-keepalive
!

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Configuring an ADSL WAN Interface Card on Cisco 1700 Series Routers
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Configuring Quality of Service Parameters
int atm0/0.1 point-to-point
pvc 0/33
vbr-rt 320 320 30
tx-ring-limit 3
protocol ppp Virtual-Template1
!
interface Virtual-Template1
bandwidth 320
ip unnumbered Loopback1
ip mroute-cache
service-policy output 1751_ADSL
ppp multilink
ppp multilink fragment-delay 4
ppp multilink interleave
!
access-list 100 permit udp any any precedence critical
!
dial-peer voice 201 voip
destination-pattern 3640200
session target ipv4:10.0.0.11
ip qos dscp cs4 media
ip qos dscp cs4 signalling
DiffServ
DiffServ addresses the clear need for relatively simple and coarse methods of categorizing traffic into
different classes and applying QoS parameters to those classes. DiffServ supports class-based marking.
Cisco Express Forwarding (CEF) mode is required for DiffServ support. To enable CEF, enter the ip cef
command.
Configuration Example
The following example shows a Cisco 1751 router configured with DiffServ:
access-list 102 permit udp host 16.0.0.4 host 15.0.0.5
access-list 103 permit udp host 16.0.0.4 host 13.0.0.5
ip cef
class-map match-all traffic-INTRA
match access-group 102
class-map match-all traffic-INTER
match access-group 103
class-map match-all traffic-dscp1
match ip dscp 1
class-map match-any traffic-prec3
match ip dscp 24
match ip dscp 25
match ip dscp 26
match ip dscp 27
policy-map ADSL-out
class traffic-INTRA
bandwidth percent 8
class traffic-dscp1
set ip dscp 5
class traffic-prec3
set ip precedence 2
class traffic-INTER
bandwidth percent 8
class class-default
fair-queue

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Configuring an ADSL WAN Interface Card on Cisco 1700 Series Routers
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Configuring Quality of Service Parameters
!
interface ATM0/0
dsl operating-mode auto
no ip address
no atm ilmi-keepalive
!
interface ATM0/0.1 point-to-point
description COLLEGAMENTO
mtu 576
ip address 1.0.0.1 255.0.0.0
pvc 99/99
protocol ip 2.0.0.2 broadcast
vbr-nrt 142 142 1
tx-ring-limit 3
oam-pvc 0
oam retry 5 5 1
encapsulation aal5snap
service-policy out ADSL-out
!
dial-peer voice 201 voip
destination-pattern 3640200
session target ipv4:14.0.0.3
playout-delay maximum 300
ip qos dscp cs4 media
ip qos dscp cs4 signaling
Committed Access Rate
Committed access rate (CAR) allows you to limit bandwidth transmission rates to traffic sources and
destinations and allows you to specify policies for handling traffic that both conforms to and breaches
the specified bandwidth allocations.
CEF mode is required for CAR support. To enable CEF, enter the ip cef command.
To enable CAR, enter the rate-limit command under the atm interface.
Configuration Example
The following example shows a Cisco 1751 router configured with CAR:
ip cef
interface ATM0/0.1 point-to-point
dsl operating-mode auto
mtu 576
ip address 10.0.0.10 255.255.255.0
rate-limit output 368000 2000 2000 conform-action set-dscp-transmit 40 exceed-action
set-dscp-transmit 48
pvc 0/33
protocol ip 10.0.0.9 broadcast
vbr-rt 160 160 1
encapsulation aal5snap
!

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Configuring an ADSL WAN Interface Card on Cisco 1700 Series Routers
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Configuring Quality of Service Parameters
Multilink PPP over ATM with Link Fragmentation and Interleaving
This feature allows multilink PPP (MLPPP) encapsulation over a single slow link to fragment and
interleave packets to a small enough size that the delay requirements of delay-sensitive traffic will be
met.
Fragment size at the MLPPP bundle can be configured by using the virtual-template interface
bandwidth command and the ppp multilink fragment-delay command. The ideal fragment size for
MLPPP over ATM should allow the fragments to fit into an exact multiple of ATM cells. These
commands calculate fragment size using the following formula:
fragment size = bandwidth x fragment-delay / 8.
For example, if the MLPPP ATM header is 10 bytes and the AAL5 packet overhead is 8 bytes, the
fragment size for MLPPP over ATM can be calculated as follows:
fragment size = 48 x # of cells - 10 - 8.
In this case, 2 cells per fragment are desirable, so the fragment size is calculated at 78 bytes.
The total bandwidth usable on this interface is 75 percent of the value declared in the bandwidth
command. To change this default value, enter the max-reserved-bandwidth command.
LLQ must be enabled when you configure MLPPP with link fragmentation and interleaving.
Note The Cisco 1700 series routers only support PPP encapsulation for MLPPP with link fragmentation
and interleaving. The dialer interface is not supported.
MLPPP + LFI Configuration
The following example shows a Cisco 1751 router configuration with MLPPP + LFI:
hostname zorro
username ruby-1 password 7 36497A4872384A
!
class-map match-all VOIP
match ip dscp 32
class-map CRITICAL
match access-group 100
!
policy-map 1751_ADSL
class CRITICAL
priority 48
class VOIP
priority 64
set ip precedence 6
!
interface ATM0/0
dsl operating-mode auto
no ip address
no atm ilmi-keepalive
!
int atm0/0.1 point-to-point
pvc 0/33
vbr-rt 160 160 1
tx-ring-limit 3
protocol ppp Virtual-Template1
!
interface Loopback1
ip address 10.0.0.10 255.255.255.255