Interoffice Trunking

[andrewgroup]

using the following example, would somebody with experience addressing the need for interoffice calling expand on the following scenario?

 

Hqrtrs has PBXnSIP on 2.2.2.2 with FQDN of pbx.newco.com extensions 100 thru 150

remote1 office on IP 3.3.3.3 with FQDN of oh.newco.com extensions 40 thru 49

remote2 office on IP 5.5.5.5 with FQDN of ky.newco.com extensions 40 thru 49

 

assuming that remote1 and remote2 do not need to call each other, only the headquarters

 

would be best served to make trunks to and from each other?

 

or can each office simple make speeddials for ext@IPaddress?

 

If you create Speed dials to an extension VIA the IP or FQDN it appears as if you conserve accounts and accomplish the same thing.

 

Hqrtrs can have phones register on remote PBX to monitor or help answer calls..

 

Then what are the benefits of trunks in this scenario?

 

What might a dial plan be at Hqrtrs if you want to dial remote1 extension 40

Dial 8 to indicate a remote office call, then dial the 2 digit office ID say 10 for remote1 and then the extension 40

So you would create a dial plan that detected a 5 digit call, strip the 8, take the next to and based on the 10 send call out a specified trunk

 

Of course the remote1 pbx receives a call and must do some matching too...

 

We get this in general terms but would like to see how others have done and learned from the same requirements.

 

I've seen posts about reducing SIP registration times, would this be important?

[Kristan]

In a similar scenario we setup the following:

 

HQ - extensions 700-799

Office1 - extensions 100-199

Office2 - extensions 500-599

 

Each office has a trunk connecting to each other office, and simply in the dial plan there is a line routing the calls, for example:

 

HQ:

Pref Trunk Pattern

25 Office1 1xx

25 Office2 5xx

 

The trunks are setup as sip gateways, not registrations, so I don't see how SIP registration times would have an issue. The PBX being called identifies the call coming in by matching the IP of the call to the outgoing proxy IP on the trunk and then routes it accordingly - same as it does for calls coming in from the ISDN gateways.

 

I tend to avoid using complex dial plans involving stripping characters etc. unless really necassary, and in this case we don't need to do anything special.

[andrewgroup]

Pref Trunk Pattern

25 Office1 1xx

25 Office2 5xx

I tend to avoid using complex dial plans involving stripping characters etc. unless really necassary, and in this case we don't need to do anything special.

 

The new CS410 come preconfigured with ext 40 through 49, prefer to use CS410 configs out of the box as much as possible for standardization

This client will likely have more than 10 remote offices (no interoffice calling required, only HQ to remote and back)

 

HQ uses extensions 100 through 199 and they are on a public IP, seems a sip gateway to HQ might be simple, But HQ back to remotes will require some logic..

 

Do you recall any dial plans that might strip and send call to a specified trunk.