Presents

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Presents IMTC Forum 2004
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SIP in the Enterprise

• Presented by François AUDET
• Nortel Networks

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Drivers for SIP in the Enterprise

• There are 2 main drivers for SIP in the
  Enterprise
• Communications Network Infrastructure
• Multimedia Applications

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Communications Network Infrastructure

• Enterprises have in the past been struggling with
  integrating SIP applications and devices in their
  corporate communications infrastructure
• Enterprises are starting to upgrade their
  corporate communications network infrastructure
  to VoIP both H.323 and SIP
• Enterprises have significant numbers of
  traditional PBXs and other telecommunication
  equipment in their corporate infrastructure
• This infrastructure needs to be upgraded
  gradually to VoIP without interruption
• The upgrading has to bring significant
  improvement in operational improvements
• IP Virtual Private Networks are commonplace
• VoIP access to the PSTN is becoming a reality

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Traditional Enterprise Telephony Network

• Complex set of TDM/Analog trunk routes configured
  statically between PBXs
• Numbering/dialing plans used to route calls
• Numbering plan/dialing plan configured locally,
  and coordinated
• Dual wiring

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VoIP Enterprise Network

• No mesh of trunk routes anymore
• Centralized numbering plan
• Signaling established directly between the Call
  Servers, or other VoIP devices

• Routing entity
• H.323 Gatekeeper
• SIP Proxy/Redirect server

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How do we get there?

• Enterprise network telephony infrastructure can
  not change overnight
• Cant forklift everything
• Has to be cost-effective
• Zero downtime
• Need to support a wide range of communication
  interfaces
• For most enterprises, the parallel VoIP network
  approach is not an option
• Too much existing functionality in network today
  is necessary
• Billing system, IVRs, Management
• Custom-built applications
• Cant change phone numbers of existing users
• Solution is to transform the existing
  infrastructure to modern VoIP infrastructure, at
  pace suitable for each Enterprise

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Nortel Meridian 1 to Nortel Communication Server
1000
Call Server (real IP PBX, direct media across
network, H.323 networking)
Stand-alone IP PBX (IP phone only, direct media,
rack-mounted)
CS 1000 software now supported on Meridian
Hardware (single stream) H.323 networking
IP-enabled PBXLine emulation and Trunk emulation
(H.323)
CS 1000 Release 1.0
CS 1000 Release 2.0
New high capacity server, redundancy, H.323 SIP
networking, SIP phones, Converged client
ITG (line)
MediaCard
Meridian 1 PBX
CS 1000(M) Release 3.0
CS 1000(M) Release 4.0
ITG (line)ITG (trunk)
MediaCard
MediaCard
ITG media card evolved from Line and H.323 GW to
slave Media Gateway
Red lines are essentially software upgrade
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SIP for the Masses

• Succession Release 3.0 brings H.323 to the masses
  
• Succession Release 4.0 brings SIP to the masses
• H.323 Gatekeeper configuration data is
  automatically supported in SIP Redirect Server
• 100 of Enterprise telephony services are
  preserved
• Including all the 400 PBX features
• H.323 to SIP networking is handled by CS 1000
• Not a protocol translator
• Call server itself handles it
• Call control in Call Server doesnt really care
  if it is SIP or H.323
• Direct media connectivity across the Enterprise
• Simplified network topology
• No physical location restrictions
• Interoperability with VoIP service providers
  (H.323 and SIP)

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Why should you care?

• Unless the Enterprise infrastructure supports
  SIP, how can you significantly deploy new SIP
  applications?
• With a SIP infrastructure, SIP applications move
  from the margins to the core enterprise
• ...but what are those SIP applications?

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Multimedia Applications
Enriching the Communications Experience
Personal Control of the Communications
Experience
Services Anywhere, Anytime

• Find-me, Guide-me
• - Simultaneous Ringing
• - Sequential Ringing
• - Re-direct messages

• Presence Management
• Personal Call Manager
• - Directory
• - Click to Call
• - Call Logs
• - Call Screening
• - IM Screening Routing
• Picture Caller ID

• Desktop Video Calling
• Instant Messaging Chat
• Multimedia Conferencing
• File sharing, Web push

On the Phone "On the Desktop"

• Provided by Nortel Multimedia Communications
  Server 5100 (MCS 5100)

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Converged Multimedia Desktop

• Allows ALL users to have access to both the FULL
  range of
• Business Telephony Services (CS 1000)
• Multimedia Services (MCS 5100)
• Includes IP phone users TDM/Analog phones
• CS 1000 Rls 4.0, MCS 5100 Rls 3.0

• Converged Desktop
• Coordinated telephony/multimedia
• Existing telephony full multimedia features

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How does it work?

• A physical phone (TDM, Analog or IP) is
  controlled by CS 1000
• UI on phone controlled by the CS 1000
• A SIP PC client on the desktop may be used for
  SIP Multimedia Services (Presence, etc.)
• One SIP session from the CS 1000, and another
  from the SIP PC Client are processed by the MCS
  5100 B2BUA
• MCS 5100 and CS 1000 synchronize their state
  information through SIP event packages
• EVERY user on the network can get a SIP Presence,
  regardless of its terminal
• From the outside, everybody is a SIP client,
  including presence, instant messaging and
  multimedia services, etc.
• Requires SIP for full version (TDM/H.323 for more
  limited set)
• Requires CS 1000 Release 4.0 (new, or Meridian
  update to CS 1000 software)

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Sample Call flow
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SIP Requirements

• SIP is a perfect solution because of subscription
  to dialog and event packages which allows calls
  servers to synchronize their call state
• Use of latest SIP standard crucial (RFC 3261,
  etc.)
• 180/183/PRACK essential for Business Telephony
  Services
• re-INVITE/UPDATE with new SDP is essential for
  Business Telephony Services
• for supporting hundreds of features, without
  rewriting them one by one
• REFER doesnt always cut it
• In a real Enterprise network, Telephone numbers
  need to be described using a formal rfc2806-bis
  format expressed as a sip URI
• sip5555_at_example.com is NOT good enough in a
  global network
• sip5555phone-contextsantaclara.example.com_at_exam
  ple.comuserphone

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Conclusions

• Support for SIP in the Communication network
  infrastructure allows for SIP for the masses in
  the Enterprise
• Preserving existing Business Telephony services,
  while introducing new SIP multimedia applications
  is crucial
• Converged client makes new SIP multimedia
  applications available to all users in the
  Enterprise, regardless of physical terminal

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Thank You