UDP source port number is missing in the SETUP response message

Question

I am working on a Wifi Display Sink application in android and am facing an issue where the source is not sending the UDP server-port number in the RTSP SETUP message.

The SETUP RESPONSE is as below

  'RTSP/1.0 200 OK
   cseq: 2
   date: Tue, 11 Aug 2015 15:12:38 +0000
   server: Mine/1.0
   session: 1719935144;timeout=60
   transport: RTP/AVP/UDP;unicast;client_port=15550-15551;
  '

NOTE: I have figured out the server-port number using tcpdump in the source device. It is 16660. It doesnot look like any specifically assigned port number as well.Seems like a random port number hardcoded into the source device for Wifi Display Application.

Is there any other way to know the server-port number to which I should listen to for incoming UDP packets?

score 1 · Answer 1 · answered Aug 13 '15 at 14:07

1

You should be listening on port 15550 and 15551 and the incoming UDP packets will contain their source port.

answered Aug 13 '15 at 14:07

ChrisWard1000

526
5
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I am sorry.. But how can you open a socket without specifying which ports to listen to?... Which is exactly what I am looking for here.... – 0xdeadbeef Aug 14 '15 at 08:25
UDP sockets listen for packets from all source ports, which the RTP server will send you. – ChrisWard1000 Aug 14 '15 at 22:30
I cannot open a client socket without specifying the port number used by the server... – 0xdeadbeef Aug 15 '15 at 03:46

UDP source port number is missing in the SETUP response message

1 Answers1