Nectar Announcement at VoiceCon and Session Border Controllers

Last week, Nectar announced the release of their Virtual Session Border Controller service (vSBC).” Nectar is notable for one of their clients’ phone service success, 1-800-FLOWERS. Based on their "Phone Options", it appears Nectar offers a hosted Avaya IP PBX service on a per seat basis. (Avaya is a Lucent spinoff and is a well known company who sells all sorts of telephone related technology, including IP PBXs.) When we came upon this announcement in VoiceCon news, we decided to write a blog on Session Border Controllers.

As some background, Session Border Controller (SBC) is something you might need to connect SIP Trunks to your IP PBX, depending on your IP PBX. Many IP PBXs have the functionality built in (Asterisk, for example). Over the last ten years, the acronym SBC has been popularized by companies selling products to telephone carriers, but the functionality is simply that of a SIP back-to-back user agent (B2BUA) configured as a VoIP gateway. SBC gets in the middle of calls between two networks.

For large enterprise SBC users, the logical trend seems to be to move the functionality to the routers, doing away with the SBC altogether. A recent white paper by Juniper covers the issue in some detail. In addition, Cisco offers integrated SBCs. Basically, SBCs are typically located at the same demarcation point as routers/firewalls, so integration seems like a sensible approach to reduce the number of parts to buy and operate.

Our position on SBCs is that they are not true peer-to-peer networking. They get in the way of end points talking to each other directly, adding a "hop" for the media to go through and potentially degrading performance. In some instances, they can prevent end-to-end encryption from being used. If you are implementing a new VoIP set-up, we don’t recommend using SBC. However, if you are using a PBX box requiring SBC, hosted SBC may be an option for you.