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Asynchronous Transfer Mode (ATM) is a connection-oriented technology. Ipriori supports Internet Protocol (IP) over Asynchronous Transfer Mode (ATM) termination on the Multi-Service Connect Module. At this time, Ipriori supports only aal5snap encapsulation.
IP over ATM is based on RFC 2684.
Configuring ATM Interfaces
Upon initial configuration of the Multi-Service Connect module in a system, interfaces are ATM capable. ATM interfaces support configuration of sub-interfaces and Permanent Virtual Circuits (PVCs) may be configured. An individual interface may support one or multiple sub-interfaces, though each sub-interface supports only one PVC (see Figure 5-1).
Figure 5-1. ATM Configuration
When connecting to an ATM switch, Integrated Local Management Interface (ILMI) may be enabled on the interfaces. ILMI monitors the bi-directional exchange of management information between UNI Management Entities (UMEs).
Other optional interface configuration commands allow users to set the UNI version, set the maximum PVCs per interface, and enter a string description for each particular ATM interface.
PROCEDURE: A sample configuration using the optional CLI commands follows:
Step 1 Use the module command to identify the module.
Step 2 Use the interface bay/slot/port command to identify the ATM interface.
Step 3 Use the ilmi-enable command to enable ILMI on the interface (optional).
Step 4 Use the ilmi-keepalive command to set the frequency of the polling request (optional).
Step 5 Use the uni-version command to set the version number if connecting to an ATM switch (optional).
Step 6 Use the max pvc command to set the maximum allowable PVCs over this interface (optional).
Step 7 Use the description command to identify this particular interface (optional).
Step 8 Use the end command to return to privileged mode.
router(config)#module 1/11 8xoc12ms
router(config-module)#no shutdown
router(config-module)#exit
router#(config)#interface atm 1/11/1
router#(config-if)atm ilmi-enable
router#(config-if)#atm ilmi-keepalive
router#(config-if)atm uni-version 4.0
router#(config-if)atm maxvc 200
router#(config-if)#description TSR 77 to ATM 843
router#(config-if)#end
router#
Configuring Sub-interfaces
After enabling ATM on the interfaces, sub-interfaces are configured over the ATM interface. Each sub-interface supports one PVC, and that PVCs must be configured on the same interfaces as the sub-interface. The naming convention for sub-interfaces is the port number and an ".n" with n representing a number. For example, 1/2/3.5 represents Bay 1, Slot 2, Port 3, sub-interface .5.
Other necessary configurations at the sub-interface level are configuring the interface's IP address (including the network mask), setting the Maximum Transmission Unit (MTU), and assigning a PVC to the sub-interface. Sub-interfaces inherit the administrative status of the interface they are configured on.
The operational status of sub-interfaces can be managed with ILMI and/or Operation, Administration, and Maintenance (OAM). ILMI provides network management and keepalive polling to ATM switches. OAM provides network fault monitoring, performance data, and diagnostic functions.
ILMI management of a sub-interface effects the operational status of PVCs. If ILMI is up on an interface, the PVC is brought up, and if ILMI is down on a sub-interface, the PVC is brought down. OAM management of a PVC operates by sending OAM loopback cells (polling) over the PVC to establish end-to-end connectivity.
Because sub-interfaces inherit the administrative status of the interface they are configured on, if either management capability is enabled but down, the PVC is kept administratively down.
PROCEDURE: A primary configuration of an ATM sub-interface might include the following:
Step 1 Use the config terminal command to enter configuration mode.
Step 2 Use the interface bay/slot/port.n (.n defines the sub-interface) command to identify the ATM interface you want to configure.
Step 3 Use the ip address and notation address to identify the ip address of the sub-interface.
Step 4 Use the description command to name the sub-interface (optional).
Step 5 Use the mtu command to enter a value for the MTU.
Step 6 Use the end command to return to interface mode.
Example: The following example show a possible initial sub-interface configuration:
router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
router(config)#interface atm 1/11/1.1
router(config-subif)#ip address 11.3.1.1
router(config-subif)#description Boston to New York
router(config-subif)#mtu 9180
router(config-subif)#end
router#
Configuring PVCs
Each PVC has a name, a Virtual Path Identifier, and a Virtual Circuit Identifier. The name of a PVC may be up to 15 alpha/numeric characters, the range for the Virtual Path Identifier is 0 to 255, and the range for the Virtual Circuit Identifier is 32 to 65535. The ATM Forum has reserved VCI identifiers 0 to 31 for control traffic.
PVCs may be created and then assigned to sub-interfaces or created and assigned at the time of their creation. A PVC must be configured on the same interface as the sub-interface.
If configuring ILMI, enable ILMI on the interface by using the ilmi-enable command. Next, create a subinterface and a PVC under this interface and use the ilmi manage command on the PVC to enable ILMI on the PVC. This allows the operational status of the ATM subinterface (and PVC) to be dependent on the establishment of ILMI connectivity. If the interface goes down, the PVC will go down. If the interface is up, the PVC is up.
OAM configuration may be used at the PVC level to monitor PVC operational status. Use the oam-pvc manage command to enable OAM management of a PVC. Once enabled, loopback cells establish end-to-end connectivity and issue notifications of connectivity failures. A OAM enabled PVC will wait for connectivity establishment before transmitting. In addition, users may define OAM parameters and the number of retries to determine link status using the oam retry command. At this time, Ipriori supports only IP Protocol and aal5snap encapsulation.
PROCEDURE: A primary configuration of an ATM PVC might include the following:
Step 1 Use the configure terminal command to enter configuration mode.
Step 2 Use the interface bay/slot/port.n (.n defines the sub-interface) command to identify the sub-interface.
Step 3 Use the pvc command to define the PVC, using alpha/numeric characters for the name and values for the VPI/VCI.
Step 4 Use the oam-pvc manage command to allow OAM management on the PVC.
Step 5 Use the protocol command to enter destination IP address.
Step 6 Use the end command to return to sub-interface mode.
Example: The following example show a possible initial PVC configuration:
router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
router(config)#interface atm 1/11/1.1
router(config-subif)#pvc pvc1 0/202
router(config-pvc)#oam-pvc manage
router(config-pvc)#protocol ip 11.3.1.2
router(config-subif)#end
router#
Displaying ATM Statistics
Use the show atm pvc command to display configuration settings for ATM PVCs.
Example: The following example displays the ATM PVCs configured on this router:
router#show atm pvc
Interface Name VPI Type Encaps Kbps Status
--------------- ---------- --- -----
----------------------- ------ ------
ATM 1/11/1.6 pvc1.6 0/105 routed AAL5-LLC/SNAP 0 Up
ATM 1/11/2 ilmipvc 0/16 ILMI AAL5-LLC/SNAP 0 Up
ATM 1/11/2.6 pvc2.6 0/105 routed AAL5-LLC/SNAP 0 Up
Use the show interface atm command to display ATM interface configurations on this router or per interface.
Example: In the following example, the show interface atm command displays the configuration for an ATM interface and two PVCs.
router#show interface atm 1/11/3
ATM 1/11/3 interface status is up
MTU 4470 bytes, BW 622.080017 Mbit/Sec
Payload BW: 601.343994 Mbit/Sec, Total BW: 622.080017 Mbit/Sec
Encapsulation ATM
Loopback: None, Keepalive: Disabled
ILMI: is Enabled, keepalive: 1, Status: DOWN
ILMI Connection Check Interval: 5, Number Of Retries: 4
VC: Max Number of VCs is 200, Current Number of VCs is 2
Signalling VC = (null), ILMI VC vpi/vci = 0/16
UNI Version: configured 4.0, negotiated 4.0, Link Side: User
VPI max bits: local 8, actual 4
VCI max bits: local 16, actual 10
Received:
123437 bytes 2329 cells
0 discards, 0 errors
Transmitted:
533816 bytes, 10072 cells
Medium Type SONET, Line Coding: NRZ, Line Type: Other
Sonet Loopback: None, Sonet Clock Source: Line
Sonet/Path: SNMP Trap sonet link-status: enabled
Tx J0 Section Trace: "1"
Rx J0 Section Trace: "1"
Tx Path Trace: "atm1/ATM 1/11/2/12"
Rx Path Trace: "<NULL>"
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Copyright © 2005
Avici Systems Inc.
Avici® and TSR®
is a registered trademark of Avici Systems Inc.
IPriori™, Composite Links™, SSR™, QSR, and NSR® are
trademarks of Avici Systems Inc.
Source
File Name: ATM.fm
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Last Updated: 02/25/05 at 15:18:05