˙Leveraging its Carrier and Enterprise VoIP leadership, Nortel
brings to market Session Initiation Protocol (SIP) Business
Trunking to allow service providers and enterprises to benefit from
the best of VoIP technology at the lowest cost and from additional
value added / revenue generating services such as Unified
Communications and Mobile Extension.
This paper discusses the SIP Business Trunking market drivers and
business case for both service providers and enterprise.
Additionally, it describes the Nortel solution which delivers on
these expectations.
What is SIP Business Trunking?
SIP Business
Trunking is an IP access technology managing several concurrent
voice calls or multimedia sessions routed over an IP connection
between the carrier VoIP network and a corporate PBX. The trunking
may pass through a SIP Gateway for conversion to PRI to support
legacy PBXs or pass through a Proxy/Redirection server for
clustering of PBXs on a single SIP trunk group. In all cases, the
corporate voice traffic is locally managed and
when necessary trunked back to the service provider as an IP
session for PSTN or intra enterprise connection.
The main benefit in using SIP Business Trunking between the
corporate PBX and the service providers VoIP infrastructure is
that there is no dedicated trunk facility - the SIP Business Trunk
is simply IP packets on a broadband IP pipe, that use a
surprisingly small amount of IP bandwidth and only when a call is
up.
There are no channels for SIP Business
Trunks
and the bandwidth is dynamic meaning zero calls active means zero
bandwidth used and adding calls in increments of one is the norm.
In other words, SIP Business Trunks can be purchased in increment
of one as opposed to legacy PRI channels which are purchased on a
per T1/E1 basis, respectively per blocks of 23/31.
The Nortel SIP Business Trunking solution is a true access trunking
technology, allowing the grouping of many SIP sessions into a
single entity for billing and maintenance, while maintaining each
sessions independence
this reflects that fact that the business is a single entity
while it's people are independent individuals.
This contrasts with a SIP line repackaging implementation,
advertised by some SIP server vendors, which does not allow
grouping for the business,
therefore leading to more costly back-office (provisioning,
billing) and maintenance activities.
From the enterprise perspective, the solution offers versatility
and reliability, connecting all users of the enterprise with the
external (PSTN)
world. The most common feature sets on the SIP Business Trunking
interface at the call level are Call Type, Calling Line ID and
Name, Circular Hunt, Call Forwarding, Release Link Trunking and
network services (e.g., hosted voicemail, ring again, etc.).
SIP is becoming the dominant protocol for next generation voice
services. The protocol and its extensions have the capability to
eventually displace all legacy PSTN mechanisms for providing voice
services.
The market opportunity
The vast majority of
companies rely on a PBX solution to manage their communications,
ranging from SMBs to large multi location enterprises.
Until recently, they have been using PRI trunking technology to
interconnect their equipment to the service provider
infrastructure. With the advent of carrier-grade VoIP technology,
where Nortel is the #1 supplier, there is now an opportunity to
drastically simplify the business trunking architecture and
therefore lower the cost for both the company and the service
provider. There is also an opportunity to create new revenue
streams for service providers,
for example, acquiring corporate customers out of their
geographical domain since the IP connection does not depend on TDM
circuits. The primary market driver for enterprises is to leverage
their broadband IP access, mostly used for IP data applications
(business applications, email, internet/intranet browsing, &), to
transport voice from their telephony CPE as an IP communication
application.
Today, broadband IP access is delivered by xDSL, Cable, Optical
Ethernet run in parallel to PRI links, which are used for voice
communications.
The transition to SIP Trunking consists of eliminating the
expensive PRI link(s) and using the often under-utilized broadband
IP pipe to carry voice. Enterprises realize the immediate benefits
of not having to purchase PRI channels in blocks of 23 (NA) or 31
(Rest of the world) - now purchasing the required voice channel
capacity in increments of one.
In other words, SIP Business Trunking introduces a paradigm shift
to communications as an IP service rather than as a physical
circuit - when compared to traditional PRI opportunities to offer
bundled voice and data services to their customer base. It is the
perfect tool to grow this market segment while laying the
foundation for future value-added services such as unified
communications.
Service providers will seize this opportunity to simplify their own
access infrastructure, capping expensive T1/E1 maintenance costs
and focusing on selling stickier voice and data services. The cost
of link engineering is also dramatically reduced when comparing the
set up of a PRI link versus the set up of a SIP trunk, since the
setup is IP based as opposed being TDM based.
As of April 2009, Infonetics Research forecasts that the SIP
Business Trunking market will grow by a CAGR of 89% to more than
$10 billion by 2013.
based PBX connectivity. PRI tied the logical access to the physical
access so that a PBX used a full E1/T1
trunk even if less capacity was required.
With SIP Business Trunking, this is no longer the case. The
business access is tied to the IP packet and therefore can operate
over any IP link, provided sufficient bandwidth is available. In
addition, because the transport medium is an IP packet, the
bandwidth is dynamic "down to the packet" allowing easy link
sharing with any other IP packet media including voice, video, data
and email. This improves and simplifies scalability, the IP layer
being
independent from the underlying connectivity: when the capacity of
the IP access pipe is increased, the SIP Business Trunk does not
require re-engineering.
This trend creates new market dynamics for service providers with
Service Provider Business IP Connectivity Market Size and
Forecast.
Source: Infonetics Research (April 2009), VoIP and UC Services and
Subscribers
Deployment options
Nortel SIP Business
Trunking solu-tion is versatile, offering multiple modes of
deployment, lowering op-erational costs and simplifying the network
for both the service pro-vider and the enterprise
· Direct to a SIP PBX: SIP Busi-ness Trunking terminates directly
on a SIP capable PBX, eliminating the need for BRI, PRI or local
PSTN cards in the PBX.
change/delete procedures without requiring the service provider to
perform any additional operational changes on the CS 2000. A single
trunk group is provisioned to a SIP Proxy Server, which in turn
serves SIP PBX, SIP [to TDM] Gateway and IP phones. The SIP Proxy
Server essentially hides the enterprise network topol-ogy from the
carrier. SIP Proxy Servers are built into routing prod-ucts such as
the Nortel Survivable SIP Proxy (SSP) server.
· To a TDM PBX via SIP [to TDM] Gateway: SIP Business Trunking
terminates on a SIP [to TDM] Gateway, which converts SIP to TDM,
allowing to retain a TDM PBX.
· To PBX Clusters via SIP Proxy Server: For a multi-site,
distributed enterprise the use of a SIP Proxy Server provides a
centralized mechanism for PSTN connection, intra-enterprise
translation and eases the PBXs / lines move/add/
The Business Case
Nortel provides business case analy-ses for both the enterprise and
the service provider. Implementing SIP trunks between its IP PBX or
gate-way, the enterprise saves by paying for only the voice
channels as op-posed to paying for a full T1/E1 for PRI. The case
below shows up to 40% cost savings, assuming a 40 seat company
requiring 8 concurrent calls (monthly PRI cost at $600 and monthly
SIP voice session at $30). This is a clear incentive for
SMB/Enterprise to migrate to SIP Busi-ness Trunking.
From the service provider perspec-tive, for less than $ 1 million
CAPEX over 5 years, the service provider can capture 50,000 PBX
seats with SIP Business Trunking and derive more than $ 8 million
in Net Present Value with a rapid pay-back period of 15 months. Our
analysis also shows that the service provider market share will
decline unless it offers SIP Business Trunk-ing to its business
customers. This is presented in the Service Provider Business Case
charts in page 4.
The Nortel Solution
Nortel enables service providers to establish SIP connectivity
between the CS 2000 and a corporate IP or TDM PBX. SIP Gateways
convert between TDM and SIP signal links and are used to retain an
existing TDM PBX, giving companies the freedom to upgrade to a SIP
PBX when the business case makes sense. In all cases, the router
CPE needs to support the Application Layer Gate-way (ALG)
functionality (e.g. Nortel SR2330 and SR4134). When a com-pany
decides to upgrade, the SIP PBX should be required to support
analog/digital existing phones and simultaneous PRI / SIP trunks
for a gradual migration (this is met by the Nortel IP PBX product
line) in order to avoid unnecessary additional costs. Additional
CPE nodes can also be included in the solution, such as a SIP Proxy
Server.
PRI Equivalency
Todays PRI trunking
solutions de-liver a rich set of features for the end-users. It is
critical to provide func-tional equivalency when migrating to SIP
Business Trunking as companies will expect identical telephony
be-havior regardless of the network based technology. Nortel has
in-vested significant time and expense in ensuring the relevant
NI-1/NI-2, ETSI, QSIG, Australian, Japanese, etc feature sets have
been ported to our SIP Business Trunking solution.
Some of the key PRI features avail-able with SIP Business Trunking
are:
- Direct Inward Dial, Direct Out-ward Dial, COMBO, FX, TIE, E800
and various other call types
- Call by Call selection enables each path to be used for incoming
or outgoing services. Conse-quently, customers are able to
opti-mize the utilization of their trunks.
- Advice of Charge (AOC)
- Network Ring Again
- Network Redirection and Reason
- Network Automatic Call Distribu-tion
- Network Message Service
- Multi switch carrier network for enterprise. (MBG)
- Equal Access
- Network Name Delivery
- Network Service Identifier Rout-ing
- 2CLI
- Dial plan management (CDP, UDP)
- Regulatory Services (LI, LNP, AIN, E800)
- Flexible Timer / Time of Day routing
- Network based tones and an-nouncements
Scalability and extensive CPE support
To
ensure the success of the solu-tion, Nortel has built in support of
up to 32,768 PBXs and has devel-oped a program to successfully
de-
- Incoming PSTN Calling Line Identification (ICLID). Enables
customers to direct calls based on the calling number and name
in-cluding TCAPNAME, or tie into a data base offering additional
infor-mation about the incoming call.
- Disaster Recovery - offers a num-ber of optional features
including Alternate Route, Re-Route Rese-lection, and Inform 911
for contin-gency planning.
- User-to-User Information and Signaling (UUI/UUS)
- Two B-Channel Transfer (TBCT) or Release Link Trunking
(RLT)
- Call Forward On Trunks (Alternate Routing to a Local Di-rectory
Number)
- Calling Name Delivery including CLASS II equivalent
- Connected Line Identification Presentation (COLP) / Connected
Line Identification Restriction (COLR)
- Calling Line Identification Presen-tation (CLIP) / Calling Line
Iden-tification Restriction (CLIR)
- Communication Diversion (Forwarding) Services (CDIV)
Over time, loss of market share as Enterprise CPE utilize SIP
Trunks.
All SIP Trunking customers go to competitors.
Service Provider Business Case (Main Assumption: market served by a
single CS 2000)
Over time, Market Share retained.
The mix of services shift but customer retention improves.
New markets open due to the virtual nature of SIP.
ploy popular IP PBX and gateways with Nortel CS 2000 SIP Server.
For example, the following products have been successfully
integrated in the field:
- Adtran Total Access 924
- Asterisk
- Cisco Call Manager CCM
- Cisco IOS router family
- Nortel BCM series
- Nortel SRG 50
- Nortel CS 1000
- Nortel CS 2100
- Nortel Survivable SIP Proxy Server
- Nortel Secure Router 4134
- OneAccess One100, One200
- Patton SmartNode SN463X
- SIPX/PINGTEL
And the following products are cur-rently in the process of being
inte-grated:
- AudioCodes Mediant 1000/2000
- Avaya S8300
- Microsoft OCS 2007
- NEC SV8100, 8300, 8500
- Nortel SCS 500
In addition, Nortel provides free of charge a generic SIP Trunking
speci-fication to enable our partners to validate against the
available SIP interface.
Nortel is an active member of the TISPAN NGN R2 and SIPConnect
standardization bodies.
Foundation for Future Investment
SIP Business Trunking lays the foun-dation for additional advanced
SIP applications that the service provider will upsell to its
business customers. For example, Unified Communica-tions will
complement business voice by delivering Multimedia and
Col-laboration services to SIP PBX users, anywhere, even if the PBX
does not support a Unified Communications solution and centrally
managed by the service provider. Mobile Exten-sion is a SIP-based
application turn-ing any mobile phone into a PBX extension,
delivering a true single number, single voice mail solution and
allowing the end-user to access
PBX features from the mobile phone.
Security
The solution security is ensured by direct connectivity between the
CS 2000 and the CPE using the TLS protocol. The CS 2000 offers the
flexibility to statically provision or to dynamically register CPE.
In the case where connectivity is going through a Session Border
Controller (carrier or enterprise based), the solution security is
ensured through verified interoperability with the SBCs NAT
Traversal and ALG capabilities.
Conclusion
In summary, SIP is becoming the dominant protocol for next
genera-tion voice services. The protocol and its extensions have
the capability to eventually displace all legacy PSTN mechanisms
for providing voice services. SIP Business Trunking is a great
opportunity for service provid-ers to simplify their network
infra-structure, reduce their cost base, avoid being left behind by
fierce competitors and get ready to deliver revenue-generating SIP
applications.
The main reasons to choose Nortel for SIP Business Trunking
are:
- Nortel delivers also advanced SIP features, such as Unified
Commu-nications and Fixed Mobile Con-vergence.
- Nortel ensures no feature loss when upgrading current PRI us-ers,
leveraging back office system investment.
- Nortel solution is non disruptive, supporting businesses with
mixed SIP/TDM PBX/Hosted lines in the same business group,
applica-ble to ANY PBX, natively for SIP PBX or through a SIP to
BRI/PRI Gateway or via Redirect and Proxy Servers.
The market is here and you can rely on Nortel, the acknowledged
leader in IP Telephony with more than 25 million lines and in IP
PBX trunking with more than a million channels.
