[VoiceOps] Session Border Controllers

Mark R Lindsey lindsey at e-c-group.com
Tue Feb 19 15:34:08 EST 2013

On Tue, Feb 19, 2013 at 1:48 PM, Grant Baxley <GBaxley at hostinfinity.com> wrote:
>>> I am looking to implement a cost effective session border controller. Can anyone point me in the right direction?
>>> We would need to be able to route calls to and from different IP addresses based on source and destination.
On Feb 19, 2013, at 15:16 , Alex Balashov <abalashov at evaristesys.com> wrote:
> On 02/19/2013 03:12 PM, Joshua Goldbard wrote:
>> Have you looked at Kamailio? We love it and it handles much higher
>> volumes than you require. We are also running on centos.
> It's quite suitable if the desire is simply to route based on that criteria.
> However, it falls apart once you start looking for to do some of the other things commercial SBCs out there do per se.

Alex, very good point: Routing calls based on From and Request-URI is really an independent problem from security functions, NAT-fixup, multi-VRF support, etc.

But, Grant, Beware: You're using a term "Session Border Controller" but only talking about the call routing function. When the Big Three (Acme Packet, Metaswitch, and Sonus) use this term, "SBC", they're referring to all of these functions:

	-- Ability to gracefully single-source and distributed handle attacks from the Internet

	-- Traffic from numerous VRFs (so that customer A's is not the same as customer B's

	-- Hosted NAT Traversal

	-- Transcoding media

	-- Lawful Intercept hooks

	-- Demultiplexed SIP trunks (so that each SIP "path" can come from a different IP address or port)

	-- Constraints like Calls-per-second or Concurrent-calls (so legitimate customers don't cause a failure)

	-- Failover from one SBC to another

	-- Distributed SBC models where one box handles signaling and many more handle media

	-- 802.1q VLAN tagging support

	-- Support for failover to BroadWorks-style registrar redundancy (where the mated registrar servers have distinct IP addresses)

	-- SNMP management

	-- Interworking SIP/UDP and SIP/TCP

	-- Jumbo SIP (SIP datagrams over 1300 bytes, out of compliance with RFC 3261)

	-- SIP/TLS and SRTP, and decryption thereof

	-- Configurable media management (to release media when possible, steer it through the SBC when not)

I use most of these features daily.

>>> mark at ecg.co +12293160013 http://ecg.co/lindsey

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