MGCP_Test: Make RTP bwe/oa format conversation tests more robust

The following testcases are carried out using two bidirectional
connections on one MGW endpoint.

MGCP_Test.TC_amr_oa_bwe_rtp_conversion
MGCP_Test.TC_amr_oa_oa_rtp_conversion
MGCP_Test.TC_amr_bwe_bwe_rtp_conversion

The test is programmed in a way that the TTCN3 side of the RTP emulation
also works in bidirectional mode. This is prone to run into a race
condition when the RX side is activated but the TX side is already
transmitting.

However, in order to test if the RTP format conversion works we do not
need to test both directions at the same time. Its perfectly fine to do
the one direction first and then do the other afterwards. Lets also add
some guard time while switching the RTP flows.

Change-Id: Idf257cfc1ab45a7f0fb6e1a2f6426f1b3145879b
1 file changed