IP to IP calls

[Oslo]

I have an IP 403 unit with three remote sites using 4620 IP sets. The IP sets can make calls to digital sets, make calls grabbing lines from the head office BUT cannot make IP to IP calls. The call is initiated, the other set rings but you cannot have a conversation as there is just dead air.
How can I resolve this problem?
Thanks for the help

 

[disturbedone]

Very odd. The VCM card is used for IP to non-IP calls so if you can make IP to digital phone and IP to trunks then this must be working.

Although it doesn't require the VCM for IP to IP calls, it does require it briefly during call setup (for DTMF recognition etc). This points to being ok too as it accepts the digits you dial and rings the phone.

Once the call is setup and it's purely IP to IP then it fails so it must have something to do with the network. You say the phones are remote to the main office - have you got any IP phones on the same LAN as the system? Do they work IP to IP?

I was going to say it could be a problem with a firewall from the remote site to the main site but if you can go across the link and hop off onto trunks then this must be ok. Weird!

Try an IP to IP call on the same LAN and see what happens.

 

[janni78]

If you have "Allow Direct Media Path" checked try to remove it and see if that works.

 

[kristiandg]

If Allow Direct Media Path is enabled, you will be telling the IP Phones, that once the call is set up, they're allowed to communicate directly with each other, thus not using a VCM resource. If these sites are firewalled in some way, the IP Phones need to be allowed to traverse the firewalls as well, but your issue will be that the phones won't be able to come back through the firewall (they may be able to leave, but not come back through). In that case, your best bet is VPN between the sites.

The quick and dirty way would be to disable ALLOW DIRECT MEDIA PATH on all the IP Phones. However, that will mean that each IP Phone will take up two VCM resources to make a call to another site's IP Phone (one for the phone, and one for the TIE line).

Hope this helps...

Kris G.

 

[Oslo]

Thanks everyone, I took off the direct media path and it allowed calls to go between two IP extensions