Here's the scenario, I have 3 IX-12IPKTD-E IP Phones that were previously setup on our corporate network. Recently, these three users moved to a remote office. I setup a site-to-site VPN using Cisco ASA 5500 series firewalls. At the remote site, all internal devices work correctly.

My issue is, the IP phones do not process the DHCP information handed out by my firewall. They sit at the "Waiting for response from DHCP Server" screen. I have verified on the ASA that the address is being handed out and that the correct MAC address of the phone is listed. So, it's as if the ASA is returning the config info, but the phone is not accepting it.

Any ideas? Thanks.

Remote IP phones work waaaaaaaaay better with static IP addresses. Get some valid addresses at the new location and configure the phones manually. If the new location is on a different subnet from the main, remember to change the IP phones RTP port from 50002 to 50004 and 50006 on the second and third phone.

I think that's what I'll do. It's weird a weird issue still. I ended up putting in a separate router with all functions tired off except DHCP and the phones grabbed and came right up.

Let me ask a quick question before I open up a new topic. Now that the phones are connected, I'm getting a lot of "jitter" when I make calls over the WAN. Local ext-to-ext are fine. I configured QoS on both sides as recommended. Any other ideas?

There is no QOS over the public internet..vpn or not. It has to be a mangaged service such as a t-1, t-3 pri or metro e. And with managed services you still need a miminum bandwith (typically 256 base and 112 kb per voip call) for H.323 up and down to not have jitter or latency.

Derrick, thanks for the reply. I set QoS using priority flow. The problem actually ended up being caused by our core switch at the corporate office that was performing Layer III routing for the network creating duplicate packets. I'm not sure why at this point, but I setup a separate router yesterday and everything cleared right up, no problems.

Still wish I could find a answer for the first question. had to setup another phone there this morning and it was a pain to have to setup a separate DHCP server just to setup a phone.

Remote phones work better with a static address. Since you have to configure the port anyway, configure the addy and save the time you would have spent on the DHCP server.