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New Member

New C40 cisco codec


I'm working for Industry Canada and we just received a new video conference system.  It is connected to a DSL line.  The video conferencing work perfect when we dial out.  But I have a issue when a external person try to dial me in, it can't connect.  I think there is a problem with local IP (modem) and dedicated IP (public IP).  I try to config. the modem but still experiencing problem with receiving calls.  

Anybody can help?          

Thank you    

Everyone's tags (3)

New C40 cisco codec

Hi Brian

For incoming call, you need use static public IP or port translation for you C40.

Also nat or firewall rule can prevent call.

Your codec must receive IP packet for following ports:1720 TCP; H.245 Range 5555-6555TCP;Video, Audio & Data/FECC Range 2326-2487 UDP ↔.

br Oleksandr

br Oleksandr
New Member

Whether we need to open all

Whether we need to open all these port on the firewall to receive incoming calls?


Cisco Employee

Re: New C40 cisco codec

For incoming call to Endpoint behind the FW/Router, you need to configure 1:1 NAT or port forwarding.

If firewall/router is H.323 awareness and support ALG, then you won’t need configure each port but most of home router will require manual port forwarding configuration.

For H.323 connection with C-series Endpoint, following ports will be use

  • Gatekeeper Discovery (RAS) – Port 1719 – UDP (not necessary for this case as not registering on GK).
  • Q.931 call Setup – Port 1720 – TCP
  • H.245 – Port Range 5555-6555– TCP
  • Video – Port Range 2326-2485 – UDP
  • Audio – Port Range 2326-2485 – UDP
  • Data/FECC – Port Range – 2326-2485 – UDP

Please note H.245 ports range is from 5555 to 6555 while port allocation configured as "Static".

If port allocation configured as "Dynamic", then port range is from 11000 to 20999.

If you modify port configuration (Static/Dynamic), codec must restart to affect configuration change.

Default RTP/RTCP port range for media is 2326 to 2485.

However this is configurable by "RTP Ports Range Start" and "RTP Ports Range Stop".