How do I unblock ports on cisco 2801 router?
Posted on 2011-09-22
I'm having a problem with a polycom trying to dial to a remote location(the service center) from our office.
The service center has tried dialing this office through a video bridge many times from the there. It rings here, but the Polycom will not pickup. However when a call is initiated from here to the bridge at the service center it will connect.
They did a port scan from there to the private IP number, 10.26.1.5, which is NATed in my router(cisco 2801) to another IP number here (192.168.1.150). The port scan shows only a few ports open, 21,23,24,80,443,990,992,993,1720, and 5001.
According to Polycom the following ports need to be open for a successful video conference:
H.323 Ports (IP based video conferencing):
• 80 - Static TCP - HTTP Interface (optional)
• 389 - Static TCP - ILS Registration (LDAP)
• 1503 - Static TCP - T.120
• 1718 - Static UDP - Gatekeeper discovery (Must be bidirectional)
• 1719 - Static UDP - Gatekeeper RAS (Must be bidirectional)
• 1720 - Static TCP - H.323 call setup (Must be bidirectional)
• 1731 - Static TCP - Audio Call Control (Must be bidirectional)
• 1024-65535 Dynamic TCP H245
• 1024-65535 Dynamic UDP - RTP (Video data)
• 1024-65535 Dynamic UDP - RTP (Audio data)
• 1024-65535 Dynamic UDP RTCP (Control Information)
As you can see that means that just about every port in existence needs to be open. The fact that they are not is probably why the video call does not connect from the bridge. It may be when this condition exists the Inbound ports are being blocked by a firewall or other device- maybe with an access list in a switch.But this is not the case here. The path is: Internet---cisco---switch---polycom.
In the meantime, a video call can connect if it is initiated from here to the service center. The question is how to open the ports up in the cisco 2801 router?