Table Of Contents
Configuring MLPPP Backhaul
Configuring the Card Type
Configuring E1 Controllers
Configuring T1 Controllers
Configuring ATM IMA
Configuring a Multilink Backhaul Interface
Creating a Multilink Bundle
Configuring PFC and ACFC
Enabling Multilink and Identifying the Multilink Interface
Configuring Additional MLPPP Settings
Enabling Real-Time Transport Protocol (RTP) Header Compression
Configuring MLPPP Backhaul
To configure an MLPPP backhaul, complete the following tasks:
•
Configuring the Card Type
•Configuring E1 Controllers
•Configuring T1 Controllers
•Configuring a Multilink Backhaul Interface
Configuring the Card Type
Perform a basic card type configuration by enabling the router, enabling an interface, and specifying the card type as described below. You might also need to enter other configuration commands, depending on the requirements for your system configuration and the protocols you plan to route on the interface.
Note In the following procedure, press the Return key after each step unless otherwise noted. At any time, you can exit the privileged level and return to the user level by entering disable at the Router# prompt.
To select and configure a card type, follow these steps:
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
card type {e1 | t1} slot subslot
Example:
Router(config)# card type e1 0 1
|
Sets the card type. The command has the following syntax:
•slot—Slot number of the interface.
•subslot—VWIC slot number.
The example shows how to configure a T1/E HWIC in the first HWIC slot as an E1 card.
When the command is used for the first time, the configuration takes effect immediately. A subsequent change in the card type does not take effect unless you enter the reload command or reboot the router.
Note When you are using the card type command to change the configuration of an installed card, you must first enter the no card type {e1 | t1} slot subslot command. Then enter the card type {e1 | t1} slot subslot command for the new configuration information.
|
Step 4
|
exit
Example:
Router#
|
Exit configuration mode.
|
Configuring E1 Controllers
Perform a basic E1 controller configuration by specifying the E1 controller, entering the clock source, specifying the channel-group, configuring the serial interface, configuring PPP encapsulation, and enabling keepalive packets. You might also need to enter other configuration commands, depending on the requirements for your system configuration and the protocols you plan to route on the interface.
Note In the following procedure, press the Return key after each step unless otherwise noted. At any time, you can exit the privileged level and return to the user level by entering disable at the Router# prompt.
To configure the E1 controllers, follow these steps in global configuration mode:
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
controller e1 slot/port
Example:
Router(config)# controller e1 0/0
Router(config-controller)#
|
Specifies the controller that you want to configure. Controller E1 0/0 maps to the T1/E1 HWIC card in HWIC slot 0.
The example shows how to specify the E1 controller as the first port of the T1/E1 HWIC card in slot 0.
|
Step 4
|
framing {crc4 | no-crc4}
Example:
Router(config-controller)# framing
crc4
|
Specifies the framing type.
|
Step 5
|
linecode {ami | hdb3}
Example:
Router(config-controller)# linecode
ami
|
Specifies the line code format.
|
Step 6
|
mode {atm | cas}
Example:
Router(config-controller)# mode cas
|
Sets the controller in ATM or channel-associated signaling (CAS) mode.
|
Step 7
|
clock source {line | internal}
[bits]
Example:
Router(config-controller)# clock
source line
|
Specifies the clocking source. The syntax is:
•line—Specifies the E1 line from which the clocking is taken.
•internal—Internal clocking.
•bits—Building Integrated Timing Supply (BITS) clocking.
The example shows how to configure the clock source for the E1 controller.
Note When you are using the clock source command to change the configuration of an installed card, you must enter the no clock source command first. Then enter the clock source command for the new configuration information.
|
Step 8
|
Router(config-controller)#
channel-group channel-no timeslots
timeslot-list speed {64}
Example:
Router(config-controller)#
channel-group 0 timeslots 1-31
speed 64
|
Specifies the channel-group and time slots to be mapped. After you configure a channel-group, the serial interface is automatically created. The syntax is:
•channel-no—ID number to identify the channel group. The valid range is from 0-30.
•timeslot-list—Timeslots (DS0s) to include in this channel-group. The valid time slots are from 1-31.
•speed {64}—The speed of the DS0.
The example configures the channel-group and time slots for the E1 controller:
Note When you are using the channel-group channel-no timeslots timeslot-list {64} command to change the configuration of an installed card, you must enter the no channel-group channel-no timeslots timeslot-list speed {64} command first. Then enter the channel-group channel-no timeslots timeslot-list {64} command for the new configuration information.
|
Step 9
|
Router(config-controller)# exit
Router(config)#
|
Exits controller configuration mode.
|
Step 10
|
interface serial slot/port:channel
Example:
Router(config)# interface serial
0/0:1
Router(config-if)#
|
Configures the serial interface. Specify the E1 slot, port number, and channel-group.
When the prompt changes to Router(config-if), you have entered interface configuration mode.
Note To see a list of the configuration commands available to you, enter ? at the prompt or press the Help key while in the configuration mode.
|
Step 11
|
Router(config-if)# encapsulation
ppp
|
Specifies PPP encapsulation on the interface.
|
Step 12
|
keepalive [period [retries]]
Example:
Router(config-if)# keepalive
[period [retries]]
|
Enables keepalive packets on the interface and specify the number of times keepalive packets are sent without a response before the router disables the interface.
|
Step 13
|
Router#
|
Exits interface configuration mode.
|
Configuring T1 Controllers
Use the following steps to perform a basic T1 controller configuration: specifying the T1 controller, specifying the framing type, specifying the line code form, specifying the channel-group and time slots to be mapped, configuring the cable length, configuring the serial interface, configuring PPP encapsulation, and enabling keepalive packets. You might also need to enter other configuration commands, depending on the requirements for your system configuration and the protocols you plan to route on the interface.
Note In the following procedure, press the Return key after each step unless otherwise noted. At any time, you can exit the privileged level and return to the user level by entering disable at the Router# prompt.
To configure the T1 interfaces, follow these steps in the global configuration mode:
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode. Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
card type {e1 | t1} slot subslot
Example:
Router(config)# card type t1 0 1
|
Sets the card type. The command has the following syntax:
•slot—Slot number of the interface.
•subslot—The VWIC slot number.
Controller T1 0/0 maps to the T1/E1 HWIC card in HWIC slot 0. The example shows how to configure a T1/E HWIC in the first HWIC slot as an T1 card.
When the command is used for the first time, the configuration takes effect immediately. A subsequent change in the card type does not take effect unless you enter the reload command or reboot the router.
Note When you are using the card type command to change the configuration of an installed card, you must first enter the no card type {e1 | t1} slot subslot command. Then enter the card type {e1 | t1} slot subslot command for the new configuration information.
|
Step 4
|
Router(config-controller)# framing
esf
|
Specifies the framing type.
|
Step 5
|
Router(config-controller)# linecode
b8zs
|
Specifies the line code format.
|
Step 6
|
Router(config-controller)# mode
{atm | cas}
|
Set the controller in ATM or channel-associated signaling (CAS) mode.
|
Step 7
|
Router(config-controller)#
channel-group 0 timeslots 1-24
speed 56
|
Specifies the channel-group and time slots to be mapped. After you configure a channel-group, the serial interface is automatically created.
Note The default speed of the channel-group is 56.
|
Step 8
|
Router(config-controller)#
cablelength {long [-15db | -22.5db
| -7.5db | 0db] short [110ft |
220ft | 330ft| 440ft | 550ft |
600ft]}
|
Configures the cable length.
|
Step 9
|
Router(config-controller)# exit
|
Exits controller configuration mode.
|
Step 10
|
Router(config)# interface serial
slot/port:channel
|
Configures the serial interface. Specify the T1 slot (always 0), port number, and channel-group.
|
Step 11
|
Router(config-if)# encapsulation
ppp
|
Enters the following command to configure PPP encapsulation.
|
Step 12
|
Router(config-if)# keepalive
[period [retries]]
|
Enables keepalive packets on the interface and specify the number of times that keepalive packets will be sent without a response the interface is brought down:
|
Step 13
|
exit
Example:
Router#
|
Exits configuration mode.
|
Configuring ATM IMA
Inverse multiplexing provides the capability to transmit and receive a single high-speed data stream over multiple slower-speed physical links. In Inverse Multiplexing over ATM (IMA), the originating stream of ATM cells is divided so that complete ATM cells are transmitted in round-robin order across the set of ATM links. Follow these steps to configure ATM IMA on the Cisco MWR 2941.
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
Router(config)# card type e1 0 0
|
Specifies the slot and port number of the E1 or T1 interface.
|
Step 4
|
Router(config)# controller E1 0/4
Router(config-controller)#
|
Specifies the controller interface on which you want to enable IMA.
|
Step 5
|
Router(config-controller)# clock
source internal
|
Set sthe clock source to internal.
|
Step 6
|
Router(config-controller)#
ima-group 0 scrambling-payload
|
Assigns the interface to an IMA group, and set the scrambling-payload parameter to randomize the ATM cell payload frames. This command assigns the interface to IMA group 0.
Note This command automatically creates an ATM0/IMAx interface.
|
Step 7
|
|
To add another member link, repeat Step 3 to Step 6.
|
Step 8
|
Router(config-controller)# exit
|
Exits the controller interface.
|
Step 9
|
interface ATMslot/IMA<group-number>
Example:
Router(config-if)#interface
atm0/ima0
|
Specify the slot location and port of IMA interface group.
•slot—The slot location of the ATM IMA port adapter.
•group-number—The group number of the IMA group.
The example specifies the slot number as 0 and the group number as 0.
Note To explicitly configure the IMA group ID for the IMA interface, you may use the optional ima group-id command. You cannot configure the same IMA group ID on two different IMA interfaces; therefore, if you configure an IMA group ID with the system-selected default ID already configured on an IMA interface, the system toggles the IMA interface to make the user-configured IMA group ID the effective IMA group ID. At the same, the system toggles the original IMA interface to select a different IMA group ID.
|
Step 10
|
Router(config-if)# no ip address
|
Disables the IP address configuration for the physical layer interface.
|
Step 11
|
Router(config-if)# atm bandwidth
dynamic
|
Specifies the ATM bandwidth as dynamic.
|
Step 12
|
Router(config-if)# no atm
ilmi-keepalive
|
Disables the Interim Local Management Interface (ILMI) keepalive parameters.
|
Step 13
|
exit
Example:
Router#
|
Exits configuration mode.
|
Note The above configuration has one IMA shorthaul with two member links (atm0/0 and atm0/1).
Configuring a Multilink Backhaul Interface
A multilink interface is a virtual interface that represents a multilink PPP bundle. The multilink interface coordinates the configuration of the bundled link, and presents a single object for the aggregate links. However, the individual PPP links that are aggregated must also be configured. Therefore, to enable multilink PPP on multiple serial interfaces, you first need to set up the multilink interface, and then configure each of the serial interfaces and add them to the same multilink interface.
Note In the following procedure, press the Return key after each step unless otherwise noted. At any time, you can exit the privileged level and return to the user level by entering disable at the Router# prompt.
The Cisco MWR 2941 router can support up to 16 E1/T1 connections through the multilink interface, ranging from 12 bundles of 1 E1/T1 each to a single bundle containing 16 E1/T1 bundles.
Complete the following tasks to configure a multilink backhaul interface.
•Creating a Multilink Bundle
•Configuring PFC and ACFC
•Enabling Multilink and Identifying the Multilink Interface
•Enabling Real-Time Transport Protocol (RTP) Header Compression
Creating a Multilink Bundle
To create a multilink bundle, follow these steps while in the global configuration mode:
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
Router(config)# interface multilink
group-number
Example:
Router(config)# interface
multilink5
Router(config-if)#
|
Creates a multilink bundle and enter the interface configuration mode:
•group-number—Number of the multilink bundle.
The example creates a multilink bundle 5.
To remove a multilink bundle, use the no form of this command.
Note To see a list of the configuration commands available to you, enter ? at the prompt or press the Help key while in the configuration mode.
|
Step 4
|
Router(config-if)# ip address
address [subnet mask]
Example:
Router(config-if)# ip address
10.10.10.2 255.255.255.0
|
Assigns an IP address to the multilink interface.
•address— IP address.
•subnet mask—Network mask of IP address.
The example configures an IP address and subnet mask.
|
Step 5
|
exit
Example:
Router#
|
Exits configuration mode.
|
Configuring PFC and ACFC
Protocol-Field-Compression (PFC) and Address-and-Control-Field-Compression (AFC) are PPP compression methods defined in RFCs 1661 and 1662. PFC allows for compression of the PPP Protocol field; ACFC allows for compression of the PPP Data Link Layer Address and Control fields.
Follow these steps to configure PFC and ACFC handling during PPP negotiation to be configured. By default, PFC/ACFC handling is not enabled.
Note The recommended PFC and ACFC handling in the Cisco MWR 2941 router is: acfc local request, acfc remote apply, pfc local request, and pfc remote apply.
Configuring PFC
To configure PFC handling during PPP negotiation, follow these steps:
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
Router(config-if)# ppp pfc local
{request | forbid}
Example:
Router(config-if)# ppp pfc local
request
|
Configures how the router handles PFC in its outbound configuration requests, use the ppp pfc local command. The syntax is as follows:
•request—The PFC option is included in outbound configuration requests.
•forbid—The PFC option is not sent in outbound configuration requests, and requests from a remote peer to add the PFC option are not accepted.
The example shows how to create a method for the router to manage PFC.
|
Step 4
|
Router(config-if)# ppp pfc remote
{apply | reject | ignore}
Example:
Router(config)# ppp pfc remote
apply
|
Specifies how the router manages the PFC option in configuration requests received from a remote peer. The syntax is as follows:
•apply—Specifies that PFC options are accepted and ACFC may be performed on frames sent to the remote peer.
•reject—Specifies that PFC options are explicitly ignored.
•ignore—Specifies that PFC options are accepted, but ACFC is not performed on frames sent to the remote peer.
The example shows how to allow PFC options to be accepted.
|
Step 5
|
exit
Example:
Router#
|
Exits configuration mode.
|
Configuring ACFC
To configure ACFC handling during PPP negotiation, follow these steps, while in interface configuration mode:
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
Router(config-if)# ppp acfc local
{request | forbid}
Example:
Router(config-if)# ppp acfc local
request
|
Specifies how the router handles ACFC in outbound configuration requests. The syntax is as follows:
•request—Specifies that the ACFC option is included in outbound configuration requests.
•forbid—Specifies that the ACFC option is not sent in outbound configuration requests, and requests from a remote peer to add the ACFC option are not accepted.
|
Step 4
|
Router(config-if)# ppp acfc remote
{apply | reject | ignore}
Example:
Router(config-if)# ppp acfc remote
apply
|
Specifies how the router handles the ACFC option in configuration requests received from a remote peer. The syntax is as follows:
•apply—ACFC options are accepted and ACFC may be performed on frames sent to the remote peer.
•reject—ACFC options are explicitly ignored.
•ignore—ACFC options are accepted, but ACFC is not performed on frames sent to the remote peer.
The example allows ACFC options to be accepted.
|
Step 5
|
exit
Example:
Router#
|
Exit configuration mode.
|
Enabling Multilink and Identifying the Multilink Interface
To enable multilink and identify the multilink interface, follow these steps, while in interface configuration mode:
Note If you modify parameters for an MLPPP bundle while it is active, the changes do not take effect until the Cisco MWR 2941 renegotiates the bundle connection.
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
Router(config-if)# ppp multilink
|
Enables multilink PPP operation.
|
Step 4
|
Router(config-if)# ppp multilink
group group-number
Example:
Router(config-if)# ppp multilink
group 5
|
Configures the identification number for the multilink interface. The syntax is as follows:
•group-number—Multilink group number.
The example restricts (identifies) the multilink interface that can be negotiated to multilink interface 5.
|
Step 5
|
Router(config-if)# keepalive
[period [retries]]
Example:
Router(config-if)# keepalive 1 5
|
Enables keepalive packets on the interface and specifies the number of times the keepalive packets are sent without a response before the router disables the interface. The syntax is as follows:
•period—(Optional) Integer value in seconds greater than 0. The default is 10.
•retries—(Optional) Specifies the number of times that the device will continue to send keepalive packets without response before bringing the interface down. Integer value greater than 1 and less than 255. If omitted, the value that was previously set is used; if no value was specified previously, the default of 5 is used.
|
Step 6
|
exit
Example:
Router#
|
Exits configuration mode.
|
MLPPP Offload
By default, the Cisco MWR 2941 offloads processing for distributed MLPPP (dMLPPP) to the network processor for improved performance. However, the Cisco MWR 2941 does not support some dMLPPP settings on offloaded bundles. The Cisco MWR 2941 does not support the following options on offloaded dMLPPP bundles:
•ppp multilink idle-link
•ppp multilink queue depth
•ppp multilink fragment maximum
•ppp multilink slippage
•ppp timeout multilink lost-fragment
Note If you have a bundle that requires the use of these options, contact Cisco support for assistance.
For more information about MLPPP offload, see MLPPP Optimization Features.
Configuring Additional MLPPP Settings
You can perform a variety of other configurations on an MLPPP bundle, including the following:
•Modifying the maximum fragment size
•Modifying fragmentation settings
•Enabling or disabling fragmentation
•Enabling or disabling interleaving
•Configuring distributed MLPPP (dMLPPP)
•Configuring multiclass MLPPP
For more information about configuring MLPPP, see the Dial Configuration Guide, Cisco IOS Release 15.0S.
Enabling Real-Time Transport Protocol (RTP) Header Compression
To enable RTP header compression, follow these steps while in the interface configuration mode:
| |
Command
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
•Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
Router(config-if)# ip rtp
header-compression [ietf-format]
[periodic-refresh]
Example:
Router(config-if)# ip rtp
header-compression ietf-format
periodic-refresh
|
Enable RTP header-compression using the ip rtp header-compression command. The syntax is as follows:
•ietf-format—(Optional) Indicates that the Internet Engineering Task Force (IETF) format of header compression will be used.
•periodic-refresh—(Optional) Indicates that the compressed IP header will be refreshed periodically.
The example enables RTP header-compression in the Internet Engineering Task Force (IETF) format by suppressing the IP ID in the RTP/UDP header compression.
Note IP header compression is only supported when MLPPP operates on the host processor; it is not supported when MLPPP is offloaded.
|
Step 4
|
exit
Example:
Router#
|
Exit configuration mode.
|
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