SCCP phone across VPN to CME

[bosseye]

All,
Our 2811 is running CME (SCCP) successfully with many 7960s/7970s, and we now have a remote office online via a router-router VPN. CME is 10.0.0.1 and remote office is 10.0.1.x. How do I get remote 7960's at 10.0.1.x to come up on CME at 10.0.0.1. As the MAC address is used by CME, I seem to remember needing some "helper" config and static to work across VPN but I cannot find this after searching. Any help would be appreciated.
br

 

[kcbell]

bosseye:

I am not sure the exact process because I was involved with a remote office setup way back!

Do you have DNS setup at your remote office to recongnize the Call Manager at 10.0.0.1 network. I think there is some standard name that Cisco used.
I think when every phone boot up. It tries to find the Call Manager and attach to it to get firmware, Calling Search Space etc. Then the Call Manager would assign an extension to it.
Some one can give more details of this process. I think you need DNS set up to know where the Call Manager is in the remote office.

kc

 

[bosseye]

Thanks - and yes - there are DNS servers at both sites. Does anyone know more about this option?

 

[meneerB]

2ways:
1) manual ipsettings on the phone on the remote location
2) setup a dhcp server on your remote, from which the phones get the ipaddress, subnet, gateway and tftp (=10.0.0.1!) server. KC is right: to get the firmware/config (no CSS, because that is handled on the CCM); DNS is normaly not used, only maybe for Extension mobility. But get DHCP ready first, and deal with this later.

1)
If you only use 1 vlan/ no vlan, try to ping the CCM from a pc on the remote location.
If you get a reply, go ahead:
go to the menu on the phone, to the ipsettings tab
**# unlocks the settings
dhcp -> OFF(!)
ip-> pick a free ipadress
subnet-> enter the correct subnet
gw-> enter the correct gateway
tftp-> enter 10.0.0.1
2) uh, yes how did I do that...;-)
ah, ok:
DHCP, setup scope option 150 TFTP Server Cisco to the 10.0.0.1 (copy/see your current dhcp scope!)
that should do the trick.

ps. if you have a local dhcp server, with no/1 default vlan, then helper addresses are not used on the switch to relay dhcp requests. If you have only one dhcp server on the main site, then it could be used. But then again, if you only have one default vlan, your pc's also couldn;t use the dhcp server. So if they work, you shouldn't worry about it.

If not: then the firewall blocks traphic.
one way audio? consult your fw-admin, thats tricky and you need to have good fw knowledge.

 

[bosseye]

I have tried and tested and now have a remote SCCP phone! Many thanks for your contributions. I also noticed that if you simply change the TFTP server on a SIP 7960 to the CME then restart the phone it has the same effect - flashing the phone into SCCP and configuring it. br