Port Loopback For Ethernet Ports; Port Loopback Without Mac Swap; Port Loopback With Mac Swap - Alcatel-Lucent 7210 SAS M Interface Configuration Manual

Port loopback for Ethernet ports

7210 devices support port loopback for ethernet ports. There are two flavors of port loopback
commands - port loopback without mac-swap and port loopback with mac-swap. Both these
commands are helpful for testing the service configuration and measuring performance parameters
such as throughput, delay, and jitter on service turn-up. Typically, a third-party external test
device is used to inject packets at desired rate into the service at a central office location.
The following sections describe the port loopback functionality

Port loopback without MAC swap

When the Port loopback command is enabled, the system enables PHY/MAC loopback on the
specified port. All the packets are sent out the port configured for loopback and received back by
the system. On ingress to the system after the loopback, the node processes the packets as per the
service configuration for the SAP.
This is recommended for use with only VLL services. This command affects all the services
configured on the port, therefore the user is advised to ensure all the configuration guidelines
mentioned for this feature in the command description are followed.

Port loopback with MAC swap

The 7210 SAS provides port loop back support with MAC swap. When the Port loopback
command is enabled, the system enables PHY/MAC loopback on the specified port. All the
packets are sent out the port configured for loopback and received back by the system. On ingress
to the system after the loopback, the node swaps the MAC addresses for the specified SAP and the
service. It only processes packets that match the specified source MAC address and destination
MAC address, while dropping packets that do not match. It processes these packets as per the
service configuration for the SAP.
This is recommended for use with only VPLS and VLL services. This command affects all the
services configured on the port, therefore the user is advised to ensure all the configuration
guidelines mentioned for this feature in the command description are followed.
7210 SAS M, T, X, R6, R12, Mxp Interface Configuration Guide
Interface Configuration
Page 33