The SBC: People just don't understand

Talk of the Session Border Controller (SBC) going away as a stand alone box is uninformed, argues Acme Packet [1] "People who don't understand the technology have these opinions," said VP Seamus Hourihan. "We've been winning the battle around the SBC since we announced our first products in 2002. It's a battle we've fought continuously."  

In fact, Acme sees SBC market growth as "high and to the right," as carriers expand their services between wireline and expanding wireless service options such as cellular, WiMAX, and femtocells.

Stuffing SBC functionality into another appliance just to simplify an equipment diagram also doesn't make a whole lot of sense to Hourihan, "If you look at the history of communications equipment, while many people have pursued [multi-function, all-in-one] 'God' boxes, none were ever bought or delivered," he said.

Acme's SBCs are performing a lot of critical functions already, including managing security, satisfying service assurance and regulatory requirements, and sorting through multiple protocols across multiple border points. "We support IPv4 to IPv6 interworking, that will be a requirement down the road," Hourihan said. "We get asked all the time to fix signaling [stuff]. We fix a lot of SIP interoperability issues. People don't understand what we really do, but it's a lot."

Transcoding and lawful intercept are two functions that make sense within the SBC rather than being shipped off and taken care of somewhere else on the network. Translation between codecs and signaling formats is typically required at the handoff between different borders while in lawful intercept the SBC is already handling both media and data flows, so directing a copy of a session to the appropriate law enforcement agency is straightforward.

Mixing up routers and firewalls with SBCs is a non-starter. "There will be products with routers, SBCs, firewalls and a bar sink in them, but not in the core," said Hourihan. It might make theoretical architectural sense to combine routers and SBCs, but from an operational and troubleshooting side it "ain't going to happen."  SBCs can support traffic from multiple router types and are more cost-effective being positioned behind the router. "You don't have to handle the full set of traffic of a router, only a subset."

For more:
- Dialogic: TDM Lives! SBCs doomed! Shopping! UC domination! [2]

Related articles:
Cisco integrates DPI, SBC [3] in new router
Acme Packet deploys open session routing [4]