TLS port numbers

Server: Asterisk 11.11.0
Client: Media5 Softphone

Ideas of debugging steps I should take will be appreciated. (Have read many articles on many websites). I like the product and hope to get past this. Wonder if it is the Softphone but … The iPad works with Media5 reliably without TLS and the iPhone is using TLS. Must be idiot user error. Thanks in advance

Background

I am having hard time getting SRTP to work reliably. I have constrained the port number so they are in the 10000-10050 range on both Asterisk and Media5 fone asking for data in the same range. All indications from TCPDump at my client router and the host are correct (see packets going to the wireless switch and also see information in the phone that packets might be present).

I have captured a situation where the system worked and failed with exactly the same port numbers which sounds like I don’t have a firewall issue. Test is a simple playback of Asterisk “Hello World”.

Failed

04:47:14.117789 IP Asterisk.10042 > Media5.10000: UDP, length 182
04:47:14.120060 IP Media5.10000 > Asterisk.10042: UDP, length 182

Worked

04:47:22.702025 IP Asterisk.10042 > Media5.10000: UDP, length 182
04:47:22.713329 IP Media5.10000 > Asterisk.10042: UDP, length 182