Q&A: What is an E-SBC?

Ask the SIP Trunk Expert

Q&A: What is an E-SBC?

By Steven Johnson, President, Ingate Systems, Inc.  |  November 04, 2013

At Ingate’s SIP Trunking Academy at ITEXPO (News - Alert) we held several sessions on the role of E-SBCs and SIP trunking. We talked the nuts and bolts of session border controllers, security, interoperability, WebRTC…you name it. I wanted to share some of the Q&As.

What does an E-SBC do?

E-SBCs sit at the edge of the enterprise network to provide control over the SIP traffic. They serve as a crucial element in enabling SIP deployments for SIP trunking, UC and soon, WebRTC.

E-SBCs resolve NAT traversal issues by securely permitting SIP signaling and related media to traverse the enterprise firewall. Without this function most companies will have one-way audio only.

Is that all that the E-SBC does?

No. E-SBCs do many other things in today’s SIP installations that make them a critical piece of the deployment. For example they can facilitate interoperability between the PBX (News - Alert) and the service provider, regardless of which IP PBX or ITSP you’re using. 

And the E-SBC does much more including:

  • Disaster Recovery: E-SBCs can reroute SIP traffic to a secondary office to keep business up and running. The E-SBC can also shift traffic to alternate service providers, or load balance to multiple PBXs on the customer’s network.
  • Quality of Service: QoS is becoming increasingly critical as high-bandwidth applications become more popular.
  • Security: The first line of defense, E-SBCs can provide authentication (which some IP PBXs do not natively support) and encryption. Deep packet inspection protects against buffer overflow attacks, denial of service attacks, sophisticated intrusions and a small percentage of worms that fit within a single packet.

Intrusion (News - Alert) detection/prevention detects DoS attacks based on SIP, and blocks malicious SIP signaling packets designed to attack certain SIP phones, servers or other devices on the LAN.

How long does it take to deploy a SIP trunk?

With the E-SBC two networks can be connected in a matter of minutes. 

Do I need to interop test my PBX and ITSP?

No. Since E-SBCs facilitate interoperability, there is no need to conduct extensive trial and error between your PBX and ITSP to get the two systems to work together. This also gives more choices to the enterprise when selecting a service provider, and permits the service provider to interact with more IP-PBXs than would be possible otherwise.

E-SBCs are an essential element in delivering SIP real-time communications to enterprises. Whether the organization is using SIP for unified communications or only for voice, the benefits of the E-SBC are numerous.

Steven Johnson (News - Alert) is president of Ingate Systems (www.ingate.com).

Edited by Stefania Viscusi