SIP Trunking Breeds New Edge Devices: OpenScape BranchSIP Trunking Breeds New Edge Devices: OpenScape Branch

Where customers want to go directly to SIP carriers from the branch, the built-in SIP trunking will be very attractive.

Earlier this month, Siemens Enterprise Communications announced a new release of OpenScape Voice. One of the highlights of Version 4 is OpenScape Branch, described as offering "scalable, feature-rich communications for cost-conscious customers with multiple branch offices." It seemed to me that every press release on branch solutions seemed to promise similar benefits, so I decided to investigate further and see what differentiated OpenScape Branch.Until recently, Siemens--like most enterprise communications vendors--offered two solutions for branch locations: a PSTN/IP gateway or a system at the branch which could be networked to a main site. The gateway or system would connect to the PSTN over traditional TI/EI/PRI trunks and to the main site over SIP. Applications that might be provided from the main site could include contact center or conferencing.

Enter SIP trunking, which is finally starting to gain market traction driven by the deployment of services from carriers like AT&T and Global Crossing. This means it is now possible to connect with other offices within the same organization or with partners and customers via SIP without the need to traverse the PSTN and without the need for dedicated circuits.

When doing branch office interconnect using SIP, however, problems of corporate firewalls and security concerns arise. A SIP-capable enterprise edge device solves this problem, and that is what Siemens has announced with OpenScape Branch. There are 50-, 250-, 1,000- and 6,000-user versions of OpenScape Branch, all managed by the same management system used for OpenScape Voice. The servers are generally IBM or Fujitsu-Siemens commercially available systems (e.g. IBM x3250 M2 for OpenScape Branch 1000).

OpenScape Branch offers some clear advantages over traditional gateways. Where customers want to go directly to SIP carriers from the branch, the built-in SIP trunking will be very attractive. Siemens has addressed security issues by including proxy and a Session Border Controller (SBC) functionality and security functions like firewall and Virtual Private Network (VPN) in OpenScape Branch. With traditional gateways these functions had to be provided externally, with additional boxes that needed to be supplied and managed in every branch office.

There is also no media server in the traditional gateway, so all tones, announcements and large conferences have to be trunked back to the media servers in that main data center. This requires additional WAN bandwidth, and makes these features unavailable at the branch when it is in isolation mode. OpenScape Branch includes a local media server for tones, announcements and conferencing, reducing the bandwidth needed to provide the same resources from a remote location.

There are two configurations of OpenScape Branch available--to support communications which are inside a corporate WAN, or over an external WAN (such as the Internet). This enables both trusted and non-trusted networking (e.g. for a franchise business), and is particularly important for cloud/branch deployments. Siemens has seen some success selling OpenScape Voice into the carrier market for hosted solutions, especially in Europe, which likely drove the creation of this new breed of device.Where customers want to go directly to SIP carriers from the branch, the built-in SIP trunking will be very attractive.