NCP500 IP address change 2

[smokeyjones]

We have a flat network into which the NCP500 is connected. The NCP500 is currently setup with static IPs of 192.168.1.8 and 192.168.1.9 pointing to 192.168.1.1 as the default gateway. The rest of the (Windows) network is setup on a 10.112.172.0 network with 10.112.172.1 as the default gateway. They were two physically separate networks until we needed to add some IP phones but are now connected into the same switches. All works as expected.

Now we are trying to bring the phones into the 10.112.172.0 network in order to simplify the setup of a VPN to a remote building and add another IP phone there. I changed the 'SIP' gateway router's IP from 192.168.1.1 to 10.112.172.2 (the main network's router is on 10.112.172.1) and changed the NCP500 IP addresses to 10.112.172.8 and 9 with its default gateway set to 10.112.172.2.

However, although the phones appear to operate correctly in that you get dial tones etc, we can't hear anything and incoming calls are not registering.

Any ideas where I'm going wrong?

Dave

 

[mlftpm]

Are you using SIP lines or POTS lines? If using SIP, the "dial tone" you are hearing is fake - it is only generated by the PBX to make users more 'comfortable' because that is how POTS operates. So if an IP phone is connected to the PBX correctly, you'll get the 'fake' dial tone, but it doesn't mean it has access to the outside world yet.

Sounds like this is the problem where you're currently at, in which case it sounds like the router for the NCP500 needs to have it's port-forwards updated also.

 

[smokeyjones]

That makes sense about the dial tone, thanks! I did suspect an issue with port forwarding although nothing looked incorrect - I'll check again in the morning. Thanks again.

 

[obtsystems]

the system gateway should be .1 which is the network router, I presume the VPN is setup on the main router

what phone are you installing?
where is the sip gateway you are setting up, if on the system, it is not a gateway but a route for voice only and for sip extensions or trunks.

the system gateway should be the network gateway/router at all times

have you changed the system address on each phone

 

[smokeyjones]

OK, so... NCP500 with DT3xx and NT551 phones

Originally, the system was setup completely separately from the main network with no physical connection between the two - there were no IP phones at this point:

NCP500 (192.168.1.8 and .9) --> SIP Gateway (Draytek Router 192.168.1.1) --> FTTP (Public IP 1)
|
|
DT3xx phones

Main Network (10.112.172.0/23) --> Main Gateway (10.112.172.1) --> FTTP (Public IP 2)

Last year, we needed to add an NT551 phone in a fibre connected building (which I think you helped me with then too) so I simply plugged a patch cable between a spare port on the Draytek router and one on the core network switch. The NT551 registered and worked perfectly.

Now, we have setup a site-to-site VPN between a remote building (10.114.172.0/24) and our main network (10.112.172.0/23) via the main gateway (10.112.172.1). We also need to add a phone in the remote building so have another NT551 to use for that.

In order to make life a little more simple (for connecting over the VPN), I thought it would be easier to move the NCP500 (and connected IP phones) to the main network. However, I didn't want to have to mess about with the external SIP side of things (changing the Public IP) hence keeping the existing 'SIP Gateway' (Draytek router) in place.

I therefore changed the IP address of the Draytek router to 10.112.172.2 and the NCP500 IPs to 10.112.172.8 and .9 with the default gateway pointing to the Draytek router (10.112.172.2). As DHCP on the main network would push the main default gateway instead, I expect to have to set a static address and the correct Default Gateway (Draytek) on the one existing IP phone. But I haven't got that far yet!

When I changed the IP addresses, I tested a couple of the DT3xx phones and found that although I could dial out, I couldn't hear anything and couldn't receive incoming calls at all.

I haven't got to the stage of trying to register/connect an IP phone in the remote building via the VPN yet.

Does that help clarify what I'm trying to achieve and where I've got to so far?

 

[obtsystems]

Then mlftm is correct if you have not re done the fwds they are still pointing to the 192 range

Do you have the vpn on the draytek or the .1 router. Because routing to the vpn on a different gateway will be a problem as it will try to route to the assigned gateway set on the phones and the system for the digital phones.

If the draytek is dual wan you could setup all on it or else go back to seperate networks ans have a vpn to the other network for the phones. It can be the same network on the far side with 2 vpns setup. One to data router and one to phone network.

 

[smokeyjones]

The VPN is setup on the .1 router and will need to stay as such. The remote network setup with two VPNs might be the way to go then - I assume I would most likely be able to use the same remote router for both VPN connections? If that works, how would I go about configuring the remote phone to connect? Would I need to register it whilst connected to the phone network prior to moving to the remote building and then change IP details accordingly?

 

[obtsystems]

I would go with 2 vpn route and yes the 2 vpns can be setup on remote router
Ip phone can be set to dhcp if you have seperate networks and once connected to the system just moving phone to remote site will work
Ip phones talking internaly will go peer to peer so they will have to be able to route to each other so 1 network with 2 gateways will cause problems

Other option is get rid of draytek and change sip trunk ip with provider and have 1 network on each side

 

[smokeyjones]

I think eventually (there are some wider network plans, including VLANing, coming up in the new year) the one network will be the way to go but in the short term, I'll give the 2 VPN route a go tomorrow and see how we get on. Thanks again.

 

[obtsystems]

Hope it works out. You will have to put the phone network back on a different subnet than the other 2 network

 

[smokeyjones]

Yes, it is already back on 192.168.1.0/24 with the main network on 10.112.172.0/23 and the remote building (via the 1 existing VPN) on 10.114.172.0/24

 

[FTPMmike]

Having .1 and .2 as two gateways on the same network is fine. It just means there are two 'gates' to the outside world. No big deal. Most static-IP and DHCP equipment will continue to point to .1 to get out, and only the equipment told to use .2 as the gateway will do so.

What is not fine, is having a 192.168.x.x and a 10.x.x.x network on the same cable without a VLAN. Mixed network traffic is a poor practice.

Option1 is to move the NCP and IP phones onto the 10.x.x.x network. You can use another gateway as you have already done, to keep the outbound data segregated. Just remember that you'll have to adjust your port-forwards, as already mentioned.

Option2 is to VLAN the two networks, to keep them isolated. If you choose the VLAN option, then you'll need to supply another DHCP server for your IP phones (not difficult), and you'll need to add the 10.x.x.x route to your VPN setup, so that the remote site knows where to route that network.

For your setup, I'd prefer Option1, but it's a personal decision. One big flat network is often faster and easier to maintain, although it does not scale as well as Option2 does (unless you use Option1 with supernetting, but that's another story).

 

[smokeyjones]

Thanks. Yes, I'm about to try heading back to one flat network but with two gateways (checking port forwarding more carefully as I obviously missed something last time!). The 2nd VPN option has proved problematic and as it was only going to be a temporary arrangement anyway, it is not worth spending time troubleshooting.

 

[smokeyjones]

Just to update this thread for future reference, I have now reconfigured the NCP500 to use the same 10.112.172.0 network but with the 2nd gateway (10.112.172.2) as default. Port forwards changed accordingly. I've setup a static route on the .2 router to the VPN network (10.114.1.0) via the .1 router.

The remote phone works as intended using DHCP and the PBX IP set accordingly.

Thanks for all the help and suggestions.