VOIP phone from third party on our network?

[ReverentCreature]

Hi all, we have recently become and academy and a load of staff have moved in to our building and bought a Cisco VOIP phone with them. Now I'm sure its not as simple as plugging their phone into an Ethernet socket on our network and away we go. But I'm not up on VOIP and I'm not sure where to start.

 

Can anyone guide me in the right direction?

 

Thanks

[localzuk]

There's a few things to consider - the ports needed for it to connect to the voip server, and whether the internet connection is good enough to support the call - ie. will it hang in there even when the net connection is super busy? Can it handle QoS being enabled to prioritise the call etc...

[FN-GM]

Are you connected in any way to the network these devices have come from?

[ReverentCreature]

We just have a basic LAN here and our network is RM CC4. We have a good broadband connection through EIS Kent so that should be okay. I'll look into what ports are required. We have no connection in any way with the Academy that these staff have arrived from.

[FN-GM]

It all depends on the back end. If they are using SIP they will be using port 5060.

 

You could create a site to site VPN. have that VPN on just one VLAN and put all these IP Phones on that one VLAN.

[localzuk]

In that case, they'll need to ensure that their VOIP server is visible to your network somehow - so at both ends you need ports opening/rules adding to firewalls to allow that traffic to traverse out of your site and into theirs.

 

It seems like a fairly large amount of work - what advantage does them not having phones on your own phone system give them?

 

It all depends on the back end. If they are using SIP they will be using port 5060.

 

You could create a site to site VPN. have that VPN on just one VLAN and put all these IP Phones on that one VLAN.

 

They need more than just 5060 - the traffic itself travels over any of a large potential range of IPs in the top end of the port list. IAX on the other hand has a much smaller port range.

Edited September 4, 2014 by localzuk

[FN-GM]

In that case, they'll need to ensure that their VOIP server is visible to your network somehow - so at both ends you need ports opening/rules adding to firewalls to allow that traffic to traverse out of your site and into theirs.

 

It seems like a fairly large amount of work - what advantage does them not having phones on your own phone system give them?

 

 

 

They need more than just 5060 - the traffic itself travels over any of a large potential range of IPs in the top end of the port list. IAX on the other hand has a much smaller port range.

 

Oh yer, forgot about that! oops

[ReverentCreature]

I see. Yes that does sound logical but never done it and not too confident about doing all of that to be honest. I'll speak with them about it as we did give them one of our phones on our network but they bought one of theirs with them too.

[ReverentCreature]

I have managed to find out the IP address of the SIP server. It seems that their VOIP system is with a third party so it should be just a matter of our LEA opening up the ports. I have been gien the details and some of it was as you suspected. Port 5060 & 5061 and so on.