SIP Trunks and Security

Security remains a top concern for many businesses and ITSPs looking into SIP trunking. How can communications routed over the public Internet or a managed connection really be secure? The fact is, with the right measures in place and with the proper planning, SIP trunk deployments can work flawlessly and be more secure than the PSTN. Here’s how:

Address interoperability — Making sure the IP-PBX (News - Alert) and ITSP are interoperable will not only smooth the way for an easy deployment, but also solve the majority of security headaches. Opportunities for hackers, spoofers, etc., are easy to come by when there are inconsistencies between these two key components. Leading IP-PBXs and ITSPs are aggressively conducting interoperability testing; make sure your equipment and service providers have demonstrated successful interoperability with one another. SIP-based edge devices also smooth out interoperability issues, “normalizing” the SIP signaling between the ITSP and IP-PBX. They also provide these normalization functions for any future changes you may make, future-proofing your SIP trunk deployments to ensure interoperability down the road.

Further simplifying vendor interoperability, the SIP Forum (News - Alert) has developed the SIPconnect Technical Recommendation, a standards-based guideline for SIP trunking between IP PBXs and VoIP service provider networks. As more service providers, PBX vendors and edge device manufacturers adopt this standard, SIP trunk implementation issues will be significantly reduced.

Employ security measures — Like other servers in the enterprise network, the IP-PBX should be protected from unauthorized access. Many firewalls today don’t adequately protect against attacks on SIP infrastructure so the edge device chosen should enforce rules and policies designed to protect this vital asset. Also, encryption can be used to reduce eavesdropping opportunities.

Authentication with the service provider — Some IP-PBX equipment can support this natively, while others cannot. A full SIP proxy firewall or other edge device may offer this capability as well, allowing enterprises with non-authenticating IP-PBXs to leverage the benefits of SIP trunking securely.

At the SIP Trunk Seminars at the ITEXPO (News - Alert) in September, in Los Angeles, we’ll be talking more about SIP trunking and security with leading experts. These seminars are free to all ITEXPO attendees. Stop by anytime to learn more — we look forward to seeing you there. IT

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

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