Alcatel-Lucent 7750 SR OS Service Manual page 1400

OAM and SAA Command Reference
Special Cases SDP Path MTU Tests — SDP Path MTU tests can be performed using the sdp-mtu size-inc
keyword to easily determine the path-mtu of a given SDP-ID. The forwarding class is assumed to be
Best-Effort Out-of-Profile. The message reply is returned with IP/GRE encapsulation from the far-
end 7750 SR.
With each OAM Echo Request sent using the size-inc parameter, a response line is displayed as
message output. The path MTU test displays incrementing packet sizes, the number sent at each size
until a reply is received and the response message.
As the request message is sent, its size value is displayed followed by a period for each request sent
of that size. Up to three requests will be sent unless a valid response is received for one of the
requests at that size. Once a response is received, the next size message is sent.
The response message indicates the result of the message request.
After the last reply has been received or response timeout, the maximum size message replied to
indicates the largest size OAM Request message that received a valid reply.
Parameters
orig-sdp-id — The SDP-ID to be used by sdp-ping, expressed as a decimal integer. The far-end
size-inc start-octets end-octets — Indicates an incremental Path MTU test will be performed with by
start-octets — The beginning size in octets of the first message sent for an incremental MTU test,
end-octets — The ending size in octets of the last message sent for an incremental MTU test,
step step-size — The number of octets to increment the message size request for each message sent
timeout seconds — The timeout parameter in seconds, expressed as a decimal integer. This value is
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address of the specified SDP-ID is the expected responder-id within each reply received. The
specified SDP-ID defines the encapsulation of the SDP tunnel encapsulation used to reach the far
end. This can be IP/GRE or MPLS. If orig-sdp-id is invalid or administratively down or
unavailable for some reason, the SDP Echo Request message is not sent and an appropriate error
message is displayed (once the interval timer expires, sdp-ping will attempt to send the next
request if required).
Values
1 — 17407
sending a series of message requests with increasing MTU sizes. The start-octets and end-octets
parameters are described below.
expressed as a decimal integer.
Values
40 — 9198
expressed as a decimal integer. The specified value must be greater than start-octets.
Values
40 — 9198
for an incremental MTU test, expressed as a decimal integer. The next size message will not be
sent until a reply is received or three messages have timed out at the current size.
If the incremented size exceeds the end-octets value, no more messages will be sent.
Default
32
Values
1 — 512
used to override the default timeout value and is the amount of time that the router will wait for
a message reply after sending the message request. Upon the expiration of message timeout, the
requesting router assumes that the message response will not be received. A 'request timeout'
message is displayed by the CLI for each message request sent that expires. Any response
received after the request times out will be silently discarded.
7750 SR OS Services Guide