test GGSN support for optional GTP-U sequence numbers
Add VTY functionality to GGSN tests, and use the VTY to enable/disable
GTP-U Tx sequence numbers in the running osmo-ggsn.
The GTPU packet template now makes sequence numbers optional.
A template created with its sequence number set to 'omit' will result in
a packet without a sequence number, i.e. the 'sequence number present' bit
in the packet header is cleared, and the sequence number field is omitted
from the encoded GTPU T-PDU packet.
Re-use the existing TC_pdp4_clients_interact() test for testing the
behaviour of osmo-ggsn. This test is now run twice, once with and
once without GTP-U Tx sequence numbers. Verify that packets relayed by
osmo-ggsn match its "g-pdu tx-sequence-numbers" configuration setting.
Change-Id: I1dc299407c61b1c865035add44067b8ab89001b3
Related: OS#2519
5 files changed