SIP

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(No Transcript)
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SIP SS7

• James Rafferty, Cantata Technology

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Agenda

• Overview
• SS7 SIP in the Converged Network
• SIP and SS7
• Applicable Standards
• Use Cases
• Challenges
• Whats Ahead?
• Resources
• Summary

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Overview

• SIP (Session Initiation Protocol) has won the IP
  Standards Wars
• SIP is an important part of the current and
  emerging IP Networks
• Most new deployments use SIP
• SIP is the key protocol for the IP Multimedia
  Subsystem (IMS)
• SS7 is the dominant signaling protocol used on
  Landline and Wireless networks
• It has been particularly successful for 2nd
  generation wireless networks

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SS7 SIP in Converged Network

• SS7 will typically be found on the edge of the
  converged network
• ISUP (ISDN User Part) used for Call Control
• TCAP (Transaction Capabilities Application Part)
  used for various database lookups such as Local
  Number Portability (LNP) and Caller Name Lookup
  (CNAM)
• SIP used for backhaul of signaling or in the core
  between gateways
• SS7 can either be converted to SIP or transported
  via SIP-T

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SIP and SS7 - Applicable Standards

• Key SS7 Standards are from ITU, ETSI and ANSI
• Country specific variants are very common
  usually based on ITU or ANSI
• Latest SIP Standard is RFC 3261
• Many additional RFCs which document additional
  methods
• Several standards for SIP SS7 interworking
• IETF RFC 3372 SIP-T
• Transfer ISUP elements via SIP with MIME body
  parts
• IETF RFC 3398 SIP SS7 Mapping
• Map ISUP parameters to SIP headers (where
  available)
• ITU-T Q.1912.5 More extensive SIP-SS7 Mapping
  with SIP-I
• SIP-I extends beyond SIP-T includes more SS7
  fields
• 3GPP TS 29.163 Similar to Q.1912.5
• This is part of the IMS suite of standards

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Use Case SS7 to SIP Conversion
Signal Transfer Point
SS7ISUP
SS7ISUP
PLMN
SS7ISUP
SIP
IPNetwork
SIP
Cell Phone
IPPhone
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Use Case SS7 Bridging via SIP-T
Signal Transfer Point
Signal Transfer Point
SS7ISUP
SS7ISUP
IPNetwork
SIP - T
SS7ISUP
SS7ISUP
PLMN/RAN
PLMN/RAN
RAN Protocols
RAN Protocols
Cell Phone
Cell Phone
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Use Case Privacy of Identity
Enforce CLIP/CLIR setting on SIP Identity Headers
CLIP/CLIR service on Privacy of Identity
Signal Transfer Point
SS7ISUP
SS7ISUP
PLMN
SS7ISUP
SIP
IPNetwork
SIP
Cell Phone
IPPhone
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Challenges

• Tremendous amount of SS7 based infrastructure in
  place
• Transition strategies for using SS7 and SIP
  together are critical to manage capital
  expenditures
• SS7 variants require switches and gateways which
  support the variants
• Non-standard uses of SIP are common and hard to
  eliminate once in the network
• Interop between equipment from different vendors
  is a way of life for the converged network
• Best of Breed Enabling Technology Components
• Creates opportunities for System Integrators

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Whats Ahead?

• Lots of momentum behind IMS, which uses both SIP
  and SS7
• More formal model for SIP use at core
• SS7 used at the edges and converted to SIP or
  SIP-I
• IMS Architecture Example
• Many operators not waiting for IMS
• Wireline vendors making extensive use of SIP as
  is
• SS7 network in place and working easier to add
  SIP for backhaul or new services
• SS7 is well entrenched for services and will
  remain in place for years to come

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IMS Architecture
SS7 signaling converted at edge
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Resources

• Internet Engineering Task Force www.ietf.org
• Provides RFCs for SIP, RTP and some aspects of
  SS7 / IP interworking
• Hitchhikers Guide to SIP
• http//www.ietf.org/internet-drafts/draft-ietf-sip
  -hitchhikers-guide-03.txt
• International Telecommunications Union
  www.itu.int
• Develops SS7 series of recommendations and NGN
• Third Generation Partnership Program (3GPP)
  www.3GPP.org
• Develops IP Multimedia Subsystem and related
  standards
• Cablelabs www.cablelabs.org
• Develops standards for Cable use of IMS
• Article Integration of SIP and SS7 for Voice
  over IP
• http//www.tmcnet.com/sip/0307/feature_articles_in
  tegration_of_sip_ss7_for_voip.htm

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Summary

• SS7 remains the dominant signaling protocol in
  todays network
• SIP is the key next generation VoIP Protocol
• Integration of SS7 and SIP critical to leverage
  existing operator investments
• Several strategies possible for transition to
  more IP centric infrastructure
• Many vendors using SIP to build new services on
  their existing SS7 network
• IMS is coming, but not the only way forward for
  operators making IP investments

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• Thank You!