Enterasys Networks X-PeditionTM Dslam Compatibility, Access Concentrator Restrictions, OAM Cells

Features

Note: This circuit can not be used for any other purpose when operating in FUNI mode.

OAM Cells

OAM cells are messages used to operate, administer, and maintain ATM networks. They provide in-band control functions for virtual circuits, including hop-by-hop and end-to-end functions such as path connectivity and delay measurement. Two distinct varieties exist, types 4 and 5, which usually comprise only a small fraction of the population of cell traffic in a typical ATM switch.

OAM cells are supported for link management as follows:

•CC - Continuity Check cells, including negotiation of use. The XSR does not originate CC cells.

•AIS - Alarm Indication Signal cells are handled as received, but the XSR does not generate them.

•RDI - Remote Defect Indication cells.

Loopback cells are echoed back to the sender. The XSR may be configured to send loopback cells as a keep-alive mechanism with the oam-pvcand oam-retrycommands.

These cells are supported over F4 (path) and F5 (circuit) flows with the following restrictions:

•End-to-end and segment-type cells are supported.

•Response cells are sent on the flow (F4 or F5) on which the request was received. An AIS cell received on a path (F4 flow) will not result in RDI response cells being sent on each circuit (F5 flow) carried by that path. The circuits however will be put in the operational down state (data will not flow) until the AIS state has been terminated.

Performance Monitoring

Cell error counts are maintained on statistics supplied by the ADSL processor. Use the show controllers atm and show interface atm commands to display ADSL statistics.

Class of Service

The XSR’s ADSL interface supports the UBR traffic class only.

DSLAM Compatibility

The XSR’s ADSL functionality is compatible with many deployed DSLAMs. Refer to your sales representative for more information.

Access Concentrator Restrictions

Consider the following restrictions for access concentrator configuration:

•All bridging protocols and operations must be disabled. Any non-user data PDUs received by the ADSL port are silently discarded.

•ILMI protocols and operations must be disabled. Any ILMI traffic received by the ADSL port are silently discarded.

XSR User’s Guide 13-7