Based on multiple Cisco docs including Cisco VT Advantage Release Notes and CUCM 7.x SRND I know that the UDP port that VT Advantage should use for video streams should be UDP port 5445. However, I also had one of field engineers report they saw UDP port 5446 when trying to setup ACLs. I have also seen a few references UDP port 5446 and Cisco VTA when searching this forum.
I have a couple of questions I was hoping someone could answer.
1. Can someone clarify if VTA uses UDP port 5446 and if so, what is it used for? Specifically, what would be VTA be communicating with when using this port.
2. I am trying to put together an ACL for a customer. The focus of the ACL is to protect the voice access network from the data network. Clearly I have to open up TCP 4224 for CAST. But I need to contend with the video stream from VTA as well. Initially the customer will have a few Cisco 7985 phones deployed and will probably deploy the 9971 stations at some point. I believe that the 7985 phones will use a range for the video RTP but if I knew for certain the VTA will always send/receive using UDP port 5445 (or even range 5445 5446) then I should still be OK. Has anyone employed an ACL in this fashion? Anyone know if the VTA port(s) are consistent and predicable for video RTP?
I would test but I don't have a 7985 in my lab.
Thanks in advance.
VTA does use both UDP 5446 and 5445. I have some issues at the moment with two VTAs talking across the WAN and have been capturing some traffic. I have seen on a successful video call that there is a single packet using UDP 5446 between the hosts and then the actual video stream uses 5445.
I have allowed both ports bi-directionally on the Firewalls between sites and video works without any issues.