Creating a VoIP system over an existing VPN

[TrueBurn]

hi

i currently have 21 locations linked through a VPN. we have one office using VoIP connecting to our main head office over a wireless link where we have a machine running Asterisk and Trixbox. i now how ever want to expand VoIP to the rest of our locations.

the problem is that the people we are currently using don't utalise SIP because "it is too hard to configure". i have been informed that SIP is the best protacall to use when VoIP is concerned.

i would like to know what would be the best options to consider when expanding VoIP to the rest of the group. is it worth my while to learn how to configure the Asterisk system myself or rather just use 3rd party consultants?

 

[Amida]

Firstly what kind of links do you have between the branches and the head office and how many people per branch?

 

[warwickw]

Also are you going to put an Asterisk server down at the branch offices and create trunks between them?

 

[TrueBurn]

Firstly what kind of links do you have between the branches and the head office and how many people per branch?

The head offices have 57 people. each of whom would require an extension. the other branches have about 130 people but each of the 19 branches will only need a single line. we only want to use the VoIP for interbranch calls. Each branch has it's own data line connecting it to the VPN with two back up proxy servers. would it be best to put an Asterisk server at each branch? can u just use IP phones at the stores then activate their extensions on the server at the head office?

 

[dmatthysen]

Each branch has it's own data line connecting it to the VPN with two back up proxy servers. would it be best to put an Asterisk server at each branch? can u just use IP phones at the stores then activate their extensions on the server at the head office?

You can have an Asterisk server at each branch which will be expensive...or you can have one Asterisk server at Head Office but in the event of any IP failure none of the IP phones will be able to make phone calls.

You can have a look at the Quintum range as they support survivability. It might also be a bit expensive (as you need one at each branch) but surely cheaper than an Asterisk server at each branch. The Quintum SSG (SIP Survivable Gateway) will allow each IP phone to make a call even if the IP Phone has lost connectivity to the Asterisk (SIP Server). And if you make an internal call (extension to extension) within the office all media is kept locally by the Quintum SSG which will save a lot of bandwidth.

 

[Lux Maharaj]

VoIP PABX: Elastix

Syrinx uses Elastix to build coporate VoIP networks that span the country. Quintum is also included to provide the reliability we require. We also terminate the voice for the corporate. We got some good reference customers - one of them in Woodmead with 400 users & users in CT, DBN etc.

 

[LynX]

The best approach would be a hosted IP Centrex approach, with Stand-Alone Survivability (SAS) at each branch office. I can recommend the Vocaltec BAX (Class5) with IPPBX funcitonality.

Or alternatively, an IPPBX variant, there are a number of SIP based IP-PBX solutions available. Like PBXnSIP and many others...

The AudioCodes gateways support Stand-Alone Survivability at each branck office together with B2BUA SIP Proxy for basic PBX functionality at each remote branch with an AudioCodes gateway, in the case of WAN failures. You may also register SIP devices, SIP phones, Soft Phons to the AudioCodes gateways with SAS.

Pls PM me your contact details a=nd intended network diagram in Visio and I will update with the best way you can to do it with AudioCodes gateways ?