Page 50 7750 SR OS Services Guide
Because services are carried in encapsulation tunnels and an SDP is an entrance to the
tunnel, an SDP has an implicit maximum transmission unit (MTU) value. The MTU for
the service tunnel can affect and interact with the MTU supported on the physical port
where the SAP is defined.
SDP Keepalives
SDP keepalives actively monitor the SDP operational state using periodic Alcatel-Lucent SDP
ping echo request and echo reply messages. Alcatel-Lucent SDP ping is a part of Alcatel-Lucent’s
suite of service diagnostics built on an Alcatel-Lucent service-level OA&M protocol. When SDP
ping is used in the SDP keepalive application, the SDP echo request and echo reply messages are a
mechanism for exchanging far-end SDP status.
Configuring SDP keepalives on a given SDP is optional. SDP keepalives for a particular SDP have
the following configurable parameters:
• Admin up/admin down state
•Hello time
• Message length
• Max drop count
• Hold down time
SDP keepalive echo request messages are only sent when the SDP is completely configured and
administratively up and SDP keepalives is administratively up. If the SDP is administratively
down, keepalives for the SDP are disabled.
SDP keepalive echo request messages are sent out periodically based on the configured Hello
Time. An optional message length for the echo request can be configured. If max drop count echo
request messages do not receive an echo reply, the SDP will immediately be brought operationally
down.
If a keepalive response is received that indicates an error condition, the SDP will immediately be
brought operationally down.
Once a response is received that indicates the error has cleared and the hold down time interval has
expired, the SDP will be eligible to be put into the operationally up state. If no other condition
prevents the operational change, the SDP will enter the operational state.
For information about configuring keepalive parameters, refer to Configuring an SDP on page 94.
To Next Page
Loading...
