tree 86d60d68b17c506152a33bb9271e8cc2a9eda523
parent 9f1f747d8ee89743951eae1db6cda2de5e5b9848
author Pau Espin Pedrol <pespin@sysmocom.de> 1667557283 +0100
committer Pau Espin Pedrol <pespin@sysmocom.de> 1667557285 +0100

gtp: Introduce VTY configurable GTP timer X3

This timer controls the amount of time a resp message transmitted by the
local gsn is to be stored in the resp queue. This is used in order to
detect duplicate requests received, since GTP states the exact same
response should be answered if a duplicate request is received.

Prior to this patch, this timer was hardcoded to 60 seconds.
This patch actually should be set, in general, to a value
equal than (T3-RESPONSE * N3-REQUESTS) values configured at
the peer, since that is the maximum period during which the local gsn
expects to receive req retransmissions from the peer.
Hence, this value must be user configurable to adapt it to the peers
connected to the GSN.

The 60 seconds hardcoded value is therefore changed to default to our
local (T3-RESPONSE * N3-REQUESTS), since the most common scenario for
osmo-ggsn/osmo-sgsn is to run it against a peer osmo-sgsn/osmo-ggsn,
which will have the same values by default.
This way we avoid by default caching response messages for way too long,
potentially filling the queue.

Related: OS#5485
Change-Id: Ia15c1cfd201d7c43e9a1d6ceb6725ddf392d2c65