Interface Configuration
7210 SAS M, T, X, R6, R12, Mxp Interface Configuration Guide Page 85
802.3ah OAM
802.3ah Clause 57 (EFM OAM) defines the Operations, Administration, and Maintenance (OAM) 
sub-layer, which provides mechanisms useful for monitoring link operation such as remote fault 
indication and remote loopback control. In general, OAM provides network operators the ability 
to monitor the health of the network and quickly determine the location of failing links or fault 
conditions. EFM OAM described in this clause provides data link layer mechanisms that 
complement applications that may reside in higher layers.
OAM information is conveyed in slow protocol frames called OAM protocol data units 
(OAMPDUs). OAMPDUs contain the appropriate control and status information used to monitor, 
test and troubleshoot OAM-enabled links. OAMPDUs traverse a single link, being passed 
between peer OAM entities, and as such, are not forwarded by MAC clients (like bridges or 
switches).
The following EFM OAM functions are supported:
• EFM OAM capability discovery.
• Active and passive modes.
• Remote failure indication — Handling of critical link events (for example, link fault, 
dying gasp)
• Loopback — A mechanism is provided to support a data link layer frame-level loopback 
mode. Both remote and local loopback modes are supported.
• Dying Gasp support on 7210 SAS platforms:
→ 7210 SAS-X, 7210 SAS-M and 7210 SAS-T, generate EFM OAM dying gasp 
messages on loss of power. EFM OAM dying gasp messages are generated on either 
Network ports or Access uplink ports based on the mode in which the device is 
operating. They are not generated on access ports. These platforms also support 
generation of SNMP dying gasp messages on power failure and it is mutually 
exclusive to generation of EFM OAM dying gasp messages. Please see the System 
Management guide for more information about support for SNMP dying gasp.
→ 7210 SAS-R6 and 7210 SAS-R12 devices do not generate SNMP or EFM OAM 
dying gasp.
→ All 7210 SAS platforms, process the received EFM OAM dying gasp, on a port 
enabled for EFM and generate a SNMP trap.
• EFM OAMPDU tunneling.
• High resolution timer for EFM OAM in 500ms interval (minimum).