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Advice on Connecting 2 Pbx servers


(Matthew Rabone) #1

I am currently running Asterisk pbx v13. It was inherited when I took over the role as system admin and while I’ve had a steep learning curve along the way it gerally served us quite well. We are now about to open z new office in the US and the time has come to make a decision on phone systems and was looking I’d you guys could give me some advice.

At present in the US they currently use a basic Comcast set up. I was offered to have a number set up in the n our UK based pbx we could forward the calls to at standard UK rates. Further investigation has yielded this may not be possible now from the US system. So now I’ve turned to looking for a better 1 size fits all to put another asterisk sever in the US and site to site vpn connect the to with Dell Sonicwalls. I’d like to know of anyone who has done this and at what success things to consider etc. The reason for doing this mainly is our support Team us based in the UK and is where calls will need to go out of US hours.

Also what would be the call rates between the two etc.

I have considered a full paid for service and am trying to weigh up all options cloud set up v the pain of on going administration. As we are currently tied to a long term contract with out sip trunk provider it’s not a decision I can take lightly (costly buy out) but one that us an option for the right solution. but I’ve found it so far to be a pretty neat system and I’m sure with a bit if work integration can be achieved …i’m sure I’ll now get shot down on this.


#2

Have you thought about setting up an IAX2 trunk between the two servers? “Free” calls! :slight_smile: https://wiki.freepbx.org/pages/viewpage.action?pageId=4161588


#3

I’m currently using an IPSEC Site-to-Site VPN to interconnect several FreePBX servers using SIP trunks between them and so far, so good.

My recommendation is to first establish the VPN connection between the two endpoints and make sure the link works as expected. Once you have established the VPN connection, then move forward with creating the SIP trunk between the FreePBX servers. If you are using either Responsive Firewall or fail2ban, take care of allowing traffic between the local and remote IPs on both sides of the VPN connection.


#4

If you’d like advice on upgrading or replacing your systems, please provide some additional details.

In the US, what type of phone system is presently installed (commercial make/model, or software version)?
How does it connect to Comcast (analog trunks sourced from Comcast MTAs, SIP to Comcast SBC, etc.)?
Approximate system size (number of phones, max. number of concurrent calls, monthly minutes in/out)?

Is the new US office a replacement (larger quarters) or an additional US location?

A possible temporary solution for after-hours support, assuming that your US system can forward incoming calls to a US number (configured either at Comcast or in your PBX):

Get a US DID from Localphone ($3 setup + $0.99/mo.) Forward this DID to your UK number ($0.006/min.) If desired, you can later set up a SIP trunk on your UK PBX that registers to Localphone to receive the calls. This eliminates the per-minute charge and may improve latency and quality a bit. If Comcast provides ‘unlimited’ nationwide calling, I recommend that you get the US DID in Westchester (New York) Zone 8. Voxbeam (a Localphone brand) is the carrier there, avoiding possible issue with a third party CLEC. This scheme is limited to two concurrent calls. If you need more, first confirm that you aren’t running against limits imposed by Comcast and/or the US PBX, then get a pay-per-minute high-channel-count DID from e.g. AnveoDirect.


(Matthew Rabone) #5

thank you for the info - i was very excited by the thought of setting up an IAX2 trunk between the two servers. @arielgrin is that what you are using between your pbx servers?

@Stewart1 thanks for the pointers, so the this will be a new office in the states replacing a smaller one will probably only house 3/4 members of staff initially, - i’m still waiting on some more details of their comcast system, and in typical fashion there has now been a spanner thrown into the mix, there are another 5 remote members of staff in the US who are currently connected the the inplace comcast system - without the full details as yet it appears they have a small cloudbased/softtphone set up, which may complicate things as i now need to work out how to connect these users to our main US office pbx? am i better off looking into cloud solution for all at this point?

so now the requirement is basically connect everyone and have calls flow both ways… is this realistically achievable


#6

I’m using SIP trunks but it can be also done as easily with IAX2


#7

Now I’m more confused. How many offices do you have? What phone system is installed in each?

Also, please get some details about the Comcast system – if it’s using proprietary softphones without open credentials, it may be difficult to impossible to integrate with your other locations.

Although a single cloud server would be simplest and easiest to manage, I wouldn’t recommend it for your application. Whichever side of the Pond it’s on, users on the other side would experience excessive latency on their local and domestic calls. Also, you’d be putting too many eggs in one basket.

Choosing between cloud and on-site systems is a complex decision. Do the locations have protected power? Redundant internet connections? Are there local resources (POTS, PRI, GSM gateway) that need to be connected? How will outages be handled (send calls to staff mobile phones, route to another office, etc.)?


(Matthew Rabone) #8

apologies @Stewart1

ok so we have 2 offices in uk main office is where pbx server located.

2nd office only use the phone system very occasionally and have to do so via VPN (this is due to the fact our pbx server routes out via a separate gateway sat on our lan which is the providers router - this is another issue i’m trying to resolve as the 2nd office can’t to connect to phone system without using vpn)

so thats main office ip range 192.168.50.1/23 main gateway 192.168.30.1 - pbx routes out via seperate providers gateway 192.168.30.252 (sat on our lan)

so currently in the US there are around 5 remote users using i believe a comcast basic cloud set up pointing softphones at cloud pbx with limited routing.

we are looking to open a new office in the us - (seperate from the remote users) in this new office will be around 4 users and is where i was thinking of putting the 2nd pbx server then connecting to out main uk office. this with use of the earlier suggestions of tunnel between the 2 would suffice for routing between the 2 sites but i’m just curious how to accomodate the remote users,

vpn? or is there a better solution?

thanks for the info on cloud set up, i was considering this i guess just to find a one size fits all just trying to find the best approach that covers all

hope that makes some sense.