Most VoIP systems can be connected through Internet using SIP trunks, to allow ‘internal’ calling which by-passes the public network, and therefore won’t incur call costs. This feature makes it possible for a business to ‘multi-site network’ its Head Office phone system, with its local, National & International Branch offices, to create one large system with a sensible dial-plan, and free calls between all company extensions.

Setting up this kind of Corporate phone network, can be complicated and difficult to maintain. This is due to the number of ‘end-points’ needed to connect the sites – and existing dial-plans may also cause conflicts. If – for example – you have five offices to connect, then each of the five offices will need four SIP Trunk groups set up on its phone system (connecting it to the other four sites). That means we would need to set up 5×4=20 SIP Trunk end-points. Each site also needs a unique 3 or 4-digit extension plan and in a lot of cases, requires an outbound call rule with a different prefix ‘steering’ digit for each link, that tells the phone system which route the call must use to get to the correct office. Sometimes the complexity of such a network gets in the way of setting it up and taking advantage of a major VoIP benefit.

Yeastar’s S-Series IP-PBX systems now incorporate a feature called ‘Multisite Interconnect’ [MI].

Multisite Interconnect

MI is a clever system designed to create links between all models of Yeastar S-Series IP-PBX systems, with the minimum amount of set-up and on-going support needed. It allows you to designate one ‘Head Office’ [Headquarter] system, and multiple ‘Branches’. Only one link is required between a branch and the headquarter system to connect it to all other offices. That means for 5 offices, only 5 network end-points need to be configured! A small amount of initial planning is required to choose a 3 or 4-digit dial-plan with a unique first digit for each site, but after that, it’s easy.

For our five-site example above, we could choose a 4-digit dial-plan across all sites, with e.g.  ‘London’ extensions being 2xxx, ‘Chelmsford’ being 3xxx, ‘Colchester’ 4xxx, ‘Ipswich’ 5xxx, and ‘Manchester’ 6xxx (alternatively, routing could also be done using the first and second digit e.g. 22xx, 23xx, 24xx etc.). On our London Yeastar, we’d edit the ‘Headquarter’ profile and create the four ‘Branch’ profiles which generate unique ID numbers and passwords for each site connection. Each profile’s extension format shows the leading digit for the extension numbers at those sites.  On the Yeastar systems at each Branch office, we simply edit the ‘Headquarter’ setting to include the public IP address of the head-office site and use the generated Branch ID and password for that office, to complete the connection. In other words, the Headquarter system is acting as a system hub …

Extension 5112 at the Ipswich office can then call a colleague at London extension 2778, by just dialling 2778 – with no call charges.

Unique & innovative

The MI solution is unique to the Yeastar S-Series product, and can be applied to all models across the range. Small offices running 5 to 10 extensions on the S20 platform can be included in networks that include S300 PBX’s supporting up to 500 users.

In addition to keeping in touch with staff at other offices, these links can also be used to forward ‘over-flow’ calls on to the same departments in other offices (e.g. Sales). Callers will be answered rather than falling to voice-mail when an office is busy …

There are no additional routing rules that need to be created to make this work, and a green-tick status icon appears on the Management page to show the link has established OK. IP exclusion rules set up on each Branch profile – and general access rules set in the Yeastar’s ‘Firewall Rules’ module – ensure that the network connections are secure. The security and simplicity of MI ensures that it will be quick & easy to put in place, reliable, and easy to maintain.

Contact Foxhall Solutions 01787 228402 – to talk about ‘Multisite-Interconnect’ telephone networks …