Designing and Planning Scalable SIP Networks

The complexity of SIP-Session Initiation Protocol networks is increasing geometrically. As with any innovation new developments are required for their widespread diffusion. As most of you know, the incredible simplicity of SIP is device independence with direct communications between endpoints. The proliferation of SIP will grow even more from machine-to-machine communications with remote endpoints solving and fixing problems without human intervention. However, one of the challenges in designing a SIP network is the use of various proxy servers to facilitate security, trunking, routing, applications and other functions. Tekelec issued a very interesting white paper on SIP Signaling Router Application Handbook. While the white paper did not address SIP proxy security (I did write about it in an earlier blog item called, The Many Flavors of SIP Trunking Solutions for SIP Systems & OCS-Office Communications Server.) Needless to say, the paper provides an excellent foundation for designing complex, scalable and future-ready networks. The five areas of discussion presented (with modifications I added) are:

1 - SIP Signaling-Server Virtualization
2 - SIP Trunking
3 - SIP Number Transparency
4 - SIP Routing
5 - SIP Proxy Peering Networks

The animated tutorial can be found at: http://www.techtionary.com/ocsforum/proxysip/
(requires Flash and please be patient with the loading)

Here are the highlights in text format:

1 - Benefits of Server Virtualization aka Abstraction - Distributed user endpoints and application servers - Scalable growth with QoS control abstraction - MACS* via signaling "abstraction" *Moves, Adds, Changes & SAS-Stand Alone Survivability - SAS enables backup for SIP devices by the multiple "abstract" local or cloud Media Gateway(s)

2 - Benefits of SIP Trunking - Session and Signaling control layers for: - On-net (IP PBX to IP PBX) - Off-net (IP PBX to local PSTN) - Off-net (IP PBX to LD/IDDD PSTN) - SPOC/SMOC-Single/Multiple Point of Connection - National control points for access (vendors) - Migration path to ALL-SIP & IMS-3GPP

3 - Benefits of Number Transparency - End-to-end media control (transparency) for voice or other media types - Access to SS7 applications for text messaging, mobility or call center routing - Enterprise control over call completion whether PSTN or SIP rather than provider - Migration path to E.164 & IMS-3GPP

4 - Benefits of SIP Routing - Eliminates "mesh" network mess - Add intelligent Session Layer 5 routing - Maintains end-to-end media transparency - Add media CoS-Classes of Service - Adds SPOC NOC-Network Operations Center - Migration path to ALL-SIP & IMS-3GPP

5 - Benefits of SIP Proxy Peering Networks - Platform for multi-vendor services - Ensures multiple CoS & QoS options - Migration path to ALL-SIP & IMS-3GPP - Foundation for any future network needs

In summary, having a SIP signaling router is viable and essential part of any domestic or global SIP communications network. More details on this concept will be presented at the OCS Forum 2010 Expo.

About OCS Forum

This tutorial is written and produced by TECHtionary.com (http://www.techtionary.com) and
OCSForum.com (http://www.ocsforum.com) sponsor of OCS Forum 2010 Expo - June 15-16 - Boulder, Colorado. OCS Forum is a vendor-independent laboratory environment designed for learning, technical guides, knowledge resources and online "live" services. OCS Forum provides planning, project management, consulting, training, case studies, white papers, speaking engagements, market/customer research, network planning and other services. For more go to http://www.ocsforum.com. Call Tom Cross 303-594-1694 or cross@gocross.com for more information and scheduling.