RTP Media Stream

[m.modashia]

Hi

From the very large range of ports that are dynamically assigned - is it possible to fix the port number for the RTP media stream on a CISCO827-4V?

[eyabane]

i don't know about the specific model/IOS you are using, but i don't think this is possible. i know you can do such things from an IP phone or a softswitch that has control over media streaming, but i seriously doubt it for a gateway. software-wise, these port numbers are recycled after a fine amount of time, which means that if you are willing to place only a signle call in/out of that box every so often, maybe you can get lucky and the box would reuse the same port numbers, but otherwise, this seems impossible, at least for now. what is wrong with the large, but well known range that is available now?

[m.modashia]

Hi Thanks for the reply. I'm not a huge expert on voice and rtp streaming and going thru a learning curve. Essentially I was wondering if it was possible to fix the ports (the 827 is the remote end) so that the head end could initiate the rtp stream. This is due to the 827 running nat and firewall and to have this large range of ports is not ideal. Any suggestion would be very helpful as most of the documentation I have read implies it is done dynamically and only dynamically.