SIP Trunking overview

SIP Trunking: The Future of Telecommunications

Presented by: John Downing, B.Eng, MBA, P.Eng

© TrainingCity 2012 1.2

Presenter John Downing

◦ co-founder of TrainingCity.◦ VoIP Training Development Lead.◦ VoIP & SIP Consultant to Telecom & Enterprise

Clients.◦ [email protected]

mailto:[email protected]


Overview In this seminar we will explore:

1. What is SIP Trunking?2. The importance of SIP: Session Initiation

Protocol3. Why customers are shifting to VoIP4. How to Sell SIP Trunking5. The Marketplace: What’s out there:

1. Legacy Trunks2. Other Carriers / ISPs3. Internet Telephony Service Providers

6. Questions & (hopefully) Answers!

Topic 1.0: What is SIP Trunking


Introduction What exactly is “S”IP Trunking?

◦ Connect the PBX to the carrier using TCP/IP data networking instead of legacy TDM (Time Division Multiplexing) Trunk technologies.

◦ SIP Trunking extends the concept to include ‘end to end’ connectivity for VoIP calls through the data network.

◦ More than just a replacement for the T-1/ISDN PRI Trunk. SIP Trunking is an “end to end” solution delivered over an IP Network.


What exactly is an IP Trunk?

◦ TCP/IP Bandwidth + SIP Signalling

◦ Bandwidth for Voice & Video transport

◦ Signalling to interconnect client VoIP infrastructure with: Other Carrier SIP Trunking Clients Carrier Provided PSTN Gateways

1.O What is SIP Trunking?


T-1 & ISDN are inefficient:

◦ Traffic Engineering for traditional PBX requires the addition of extra T-1 or PRI in groups of 24/23 channels.

◦ Bandwidth for SIP Trunking can be made available in any increment.

◦ SIP Trunking is more than just a replacement for TDM Trunks. It is a solution for “end to end” VoIP connectivity & integral to all future Carrier Value Added Service offerings.

◦ Irony is that SIP, a TCP/IP Protocol, may finally achieve the carrier’s old SS7 dream of an “Intelligent Network” offering.

1.0 Why SIP Trunking?


1.0 Traditional PSTN Access using ISDN PRI “Trunk”


One IP PBX PSTN Gateways with TDM Trunks distributed

geographically.

1.0 SIP Trunking to Client PSTN Gateway


One IP PBX PSTN Gateways with TDM Trunks distributed

geographically.

1.0 SIP Trunking to Client PSTN Gateway

SIP TRUNK CONCEPT


SIP Trunking can scale more easily than legacy ISDN PRI Trunks.

The Physical Layer of SIP Trunking is “any” available bandwidth, not limited to incremental additions of PSTN circuits and associated PBX hardware.

If a client needs more VoIP calling capability at a specific site, add additional bandwidth to access router.

1.0 Scale with SIP Trunking


Use existing WAN for interconnectivity of Offices:

◦ A multi-site corporate client can optimize its supply chain by eliminating contractual arrangements with multiple PSTN access providers.

◦ Use existing WAN to backhaul VoIP calls to Rogers supplied PSTN Gateways.

1.0 WAN Bandwidth used for SIP Trunking


Hard to get head around idea that a SIP Trunk extends through the WAN. For a client this means a SIP Trunk could connect their corporate LAN to any PSTN Gateway in the Carrier WAN, or another client of the Carrier.

Next step is to offer Trusted SIP Peering arrangements with other carriers.

1.0 Connectivity through the WAN

Topic 2.0: Session Initiation Protocol (SIP)


2.0 Intro to SIP SIP defined in RFC 3261

◦ Establish & manage multimedia sessions.◦ Client / Server : Request / Response Architecture◦ Similar to HTTP:

SIP/UDP/IP/Layer 2 May use Session Description Protocol

SDP/SIP/UDP/IP/Layer 2

◦ Exchange SIP messages between end points


2.0 Intro to SIP Overview SIP dominates Enterprise and Carrier VoIP,

Video, & Multimedia deployments. All equipment vendors actively support

standard. Other VoIP Signaling standards are obsolete:

◦ H.323◦ MGCP◦ Vendor Specific such as Cisco SCCP◦ IAX2 (Possible exception: Asterisk specific and ETF

std)


SIP is part of TCP/IP. Considered an Application Layer Protocol in

TCP/IP just let HTTP & FTP. Works the same way.

SIP messages use regular TCP/IP packets for transport from IP Phone to IP PBX.

Takes advantage of all IP Security.

2.0 Understanding SIP


SIP Does not transmit the voice directly.

SIP “sets up” the Voice Over IP packets for transmission. Voice is sent using a protocol called Real Time Protocol (RTP).



VoIP consists of two sets of IP Packets:

◦ Real Time Protocol (RTP) packets Often referred to as an “RTP Stream” because the

voice (and video) is actually carried in RTP.

◦ Session Initiation Protocol (SIP) Packets SIP Packets, or SIP messages as they are called,

setup and teardown the RTP Streams.



2.0 SIP User Agents

5.20

UserAgentClient

UserAgentServer

UserAgentClient

UserAgentServer

CALLEECALLER

INVITE

Client sends a request message

200 OK

Server sends back a response message


VoIP calls consist of SIP Messages Signalling and Real Time Protocol Packets to transport the voice.

As only a few SIP messages are needed to setup most VoIP calls, the bulk of the Bandwidth requirement is for the RTP Streams

2.0 Introduction to SIP


2.0 Intro to SIP

Item

• Standard• Relationship

• Servers

SIP

• IETF• Peer to Peer &

Client Server• Proxy, Registrar,

Location, Redirect


2.0 Intro to SIP

Item

• Media Capabilities Exchange

• Security

• Quality of Service

SIP

• Uses Session Description Protocol

• ITEF Standards, TLS, IPSec, etc.

• IETF Standards, DiffServ, RSVP, etc.


SIP is the signalling standard for all Voice & Video over IP.

SIP is unlikely to be replaced any time soon.

Lots of innovation occurring around SIP.

Clients need to prepare for a world where TDM Legacy voice is no longer supported.

2.0 SIP Conclusion

3.0 Shifting Clients to VoIP


PSTN (Public Switched Telephone Network):◦ Transport of Voice using concept of Circuits

TDM - Time Division Multiplexing examples such as T-1, ISDN PRI.

Analog “CO” circuits.◦ Signalling:

Various access technology standards build around core network signalling based on SS7.

VoIP:◦ Transport over IP (Packet) networks

Layer 2/IP/UDP/RTP/Codec◦ Signalling using SIP – Session Initiation Protocol

Layer 2/IP/UDP/SIP

3.0 Compare Circuit PSTN and VoIP


VoIP Challenges include:1. Meeting all the specific requirements of

“making a phone call”: IT networks designed for “best effort”, shared

infrastructure, & optimized to minimize cost while providing reasonable service.

2. Regulatory requirements: Calling 911 law enforcement intercepts Billing & Tariffs

3.0 VoIP Challenges


Challenges:◦ Multi-vendor legacy PBX support

Geographic & Multi-vendor specific PBX support demands.

◦ Carrier/Supplier Management Need separate carrier agreements for many diverse

locations.◦ Physical Plant

Maintaining facilities for large, complex PBX Hardware.

3.0 SIP Trunking for the Enterprise


Core components of Enterprise VoIP include:◦ IP Phones◦ IP PBX◦ PSTN Gateway(s)◦ Session Border Controller

In carrier infrastructure the focus is on transport. Rather than an IP PBX the carrier may deploy a “soft switch” server.

3.0 VoIP Equipment


Two basic types of IP PBXs in the market today:◦ Legacy PBXs that are also VoIP enabled.◦ “Pure” VoIP IP PBX.

3.0 IP PBX


Phones connect to LAN using Ethernet + TCP/IP.

PBX becomes an “IP” PBX. Also uses Ethernet + TCP/IP.

No need for PSTN trunks when calling another VoIP Phone in the network.

PSTN trunks can be accessed using a VoIP/PSTN Gateway.

3.0 VoIP uses Ethernet & TCP/IP


IP PBX replicates functionality of 1990s proprietary TDM PBX:◦ All the features of a PBX replicated in VoIP:

Call forward Do Not Disturb Transfer, Hold, etc, etc, etc.

Now just another Server on the network:◦ Add on functionality such as Voice Mail can be

“outsourced” to a dedicated “Voice Mail Server”.◦ Same for IVR (Interactive Voice Response) or any

other function.

3.0 VoIP Equipment: IP PBX


The PSTN Gateway device is designed to convert:◦ VoIP transport to/from Circuit transport

Layer 2/IP/UDP/RTP/Codec to/from TDM Codec◦ SIP signals to SS7 based PSTN signals

Layer 2/IP/UDP/SIP to/from Q.Sig or ISUP based SS7 The PSTN Gateway may also have to

perform codec conversion:◦ PSTN T-1 interface requires G.711 µ-Law but VoIP

transport sent voice encoded in G.729.

3.0 VoIP Equipment: PSTN Gateway


SBC provides “Web Proxy Server” functionality for VoIP & SIP. Note that RTP Streams and SIP Dialogs both connect through the SBC.

3.0 Session Border Controller


SIP Trunk implies much more than just “over T-1”. Some clients may think this is all SIP trunking offers.

3.0 SIP Trunk “over T-1”


Corporations may opt for Private PSTN Gateways. “SIP Trunking” on their WAN.

Still can offer access to RBS PSTN Gateways & other QoS management services.

3.0 Enterprise VoIP Deployment.


3.0 Managed SIP Trunk to RBS


Client with several locations can use SIP Trunking over an IP WAN to interconnect their IP PBXs.

Provide incoming and outgoing calls to the PSTN through the supplied SIP Trunks. Client no longer requires T-1 or PRI trunks at every location, just access to the WAN.

3.0 What can we Offer with SIP Trunking?


Solution with SIP Trunking must include:◦ Provide all basic call services, LD, DID, Toll Free,

CLID, etc.◦ Shared bandwidth usage across the WAN. Setup

SLAs to permit client to scale Quality Assured VoIP bandwidth across multiple WAN access locations.

◦ E-911 support.◦ Redundancy & backup.◦ Security

Private Network VPN connectivity for VoIP & SIP traffic Secure codecs, SIPs, SRTP, should all be supported.

3.0 SIP Trunking for the Enterprise


3.0 PSTN Gateways in LANs


3.0 IP Trunks from WAN Service Provider


Client can trust Rogers to provide secure access to VoIP

3.0 Managed SIP Trunking


3.0 Internet Telephony Service Provider: ITSP


Yes it works if configured properly. Option One:

◦ Route call to 911 contact centre, tell operator location, then get routed to correct Public Safety Answering Point (PSAP).

Option Two:◦ Deploy at least one local PSTN gateway and

associated PSTN trunk at each location, configure SIP to send all 911 calls to locally (LAN) deployed PSTN Gateway.

3.0 911 Support with SIP Trunking

4.0 Selling IP Trunking


Ideas to Start Client Conversations:

◦ SIP is the Future. No one is still developing old TDM equipment. Sooner or later old TDM PBX equipment will reach “end of life”. Get out in

front of impending requirements.

◦ All sorts of SIP enabled Unified Communications solutions are out there. Opportunities to align business processes with productive SIP enabled

solutions are endless:

Unified Communications: email/vmail/messaging/social media.

Customer interaction solutions.

Contact Centre integration (infinitely easier & better than old TDM solutions from the 1990s!)

4.0 Selling SIP


Important to educate client on idea that SIP Trunking is more than just a replacement for old TDM access trunks.

SIP Trunks extend IP PBX call control into the WAN.

SIP Trunks allow client to access RBS PSTN Gateways… AND RBS Services!

◦ Amazing opportunity for RBS to (finally) start offering enterprise grade managed voice/video/productivity solution(s).

4.0 Selling SIP Trunking


Clients will be looking for a wide range of capabilities including:◦ Protocol Support◦ Service Providers technical capabilities◦ Cost◦ Security◦ Availability◦ Interface options & protocol support◦ Network geographically diversity.◦ Path to Unified Communications

4.0 Choosing a SIP Provider


Internet Telephony Service Providers range from Vonage to “Basement BBS Guys”.◦ They scale with the Internet, but so does RBS.◦ Hard for enterprise clients (& IP PBX vendors) to

know who to trust. Rogers is a trusted WAN partner with extraordinary

security & reliability expertise. ITSP is “fly by night”, accident waiting to happen

with confidential information.

4.0 Differentiating RBS from ITSPs


Beyond the SIP Trunk to PSTN Gateway, think about managed SIP Services:◦ Voice Mail Servers◦ Contact /Social Media Centre scaling◦ Content Server integration

Security, Security, Security◦ You’ve got private WAN capability◦ You can secure VoIP traffic that needs to flow into

The Internet through Session Border Controllers & Application Gateways.

4.0 Differentiating from Bell & other Carriers


Partner with other geographically diverse Carriers to offer “Trusted SIP Trunks” to other jurisdictions.◦ Offer clients secure SIP trunking solution that

reaches USA & global locations.

4.0 Differentiating from Bell & other Carriers


Small to Medium Enterprise clients benefit:◦ Combine voice & data network access.◦ Eliminate onsite TDM trunks to PSTN by using

Gateways.◦ Reduce capital costs.◦ Take advantage of SIP based productivity

enhancement features associated with IP PBXs such as: Unified Communications Follow me features Etc.

4.0 SIP Trunking for SME


Clients of RBS could:◦ Avoid the requirement to maintain multiple-facility

TDM solutions.◦ Establish a point of presence without having to

build local facilities.◦ Point E.164 numbers to any trunk group/IP

address/URL◦ Provision and Scale On Demand◦ Port over existing PSTN DID numbers

4.0 Wholesale Offerings with SIP Trunking


Not just PRI replacement◦ Multiple locations served from a single IP PBX

Capital and expense savings with converged solutions

Support features like single number service Multi-location services SIP trunks more flexible and efficient

◦ Part of business case to support UC deployment

4.0 Other Considerations


SIP Trunking is not just a “trunk replacement”

It is migration from TDM to Voice over the data network.

Is equipment SIP compliant? Professional services to perform:

◦ Protocol check◦ Project Management◦ Capacity planning

4.0 Need to Revisit Total Voice Network


Voice networking still dominated by TDM infrastructure.

SIP Trunking is an enabling technology◦ Brings UC to organizations

How to evolve Voice infrastructure to SIP Trunking

How to choose a SIP Trunking service provider.

4.0 Selling SIP: Conclusions

5.0 Know the Competition


Breaks down into three main groups:

◦ Internet Telephony Service Providers (ITSP) Skype/Microsoft, Vonage, Google, “no name” small

players◦ Traditional Carriers

Bell, Verizon◦ Unexpected entrants

Akamai?

5.0 SIP Competitors


ITSPs range from major players to “one guy in his parent’s basement:◦ Can’t dismiss either, lots of great companies

started in garages.◦ Major players Vonage & Skype◦ Hard to dismiss the 800,000,000,000 Gorilla

called “Google”.◦ Mid sized players.◦ Small ITSPs that offer all sorts of quasi-legal VoIP

services globally.

5.0 SIP Competitors - ITSPs


Geographical access still defines much SIP Carrier competition.

Need ability to offer corporate clients physical access to carrier WAN.

Regulatory issues remain important, but not as strict as legacy PSTN.

Bottom line, usual suspects… for now.

5.0 SIP Competitors - Carriers


Bell offers SIP services to large enterprise customers in Ontario & Quebec.

Expanding in West

Rolling out SIP to SMEs over past year.

Reputation for excellent in SIP knowledge. Working to “change the culture” of the company to VoIP & SIP through effective Training & Education programs.

5.0 SIP Trunking Availability from Bell


Must have MPLS VPN (Layer 3 or Layer 2 Ethernet) connectivity to access SIP Trunking.

Voice Quality◦ Provisioning the right QoS in the Data Network,

engineer for voice with strict considerations for packet loss, jitter, & latenancy.

Bell offers clients the option to access their traffic status, usage of SIP trunking bandwidth.

Service Level Objectives:◦ Mean Time to Repair 4 hours◦ Availability 99.9%

5.0 Bell SIP Trunking


Long Distance pricing◦ No more long distance for calls internal on WAN◦ Make calls from IP PBX to any rate centre with

trunk group in place◦ Calls on trunk groups that are not local to the

destination charged according to rate plan.

5.0 Bell SIP Trunking


Verizon offers a wholesale SIP Gateway service:◦ Uses IPSec to transmit SIP & RTP (VoIP calls)

between client carrier network & Verizon network.◦ Client can access multiple Verizon PSTN

Gateways.◦ Termination of both local & long distance to/from

Verizon SIP/VoIP network to PSTN.◦ Includes support for FTNA (Foreign Telephone

Number Assignment capability.

5.0 Wholesale SIP Gateway Service - Verizon


Verizon offers a wholesale SIP Gateway service:◦ Pricing models vary with carrier client

requirements.◦ Monthly recurring charges◦ Non-recurring charges for specific services◦ Metered per minute pricing◦ Domestic usage rates based on terminating Local

Access & Transport Area (LATA) or classification of the terminating Local Exchange Carrier (LEC) based on the dialed NPA-NXX.

5.0 Wholesale Verizon SIP Gateway Service


◦ As long as a proper mixture of Interstate and Intrastate rates can be maintained, discounts are available for certain call jurisdictions.

◦ Interstate- and intrastate-defined traffic will rate at a six-second minimum/six-second increment.

◦ The international rate structure is based on the terminating location (landline and wireless termination).

◦ The extended domestic traffic will rate at a six-second minimum/six-second increment.

◦ The international traffic will rate at a 30-second minimum/six-second increment, except for Mexico, which will rate at a 60-second minimum/60-second increment.

◦ http://www22.verizon.com/wholesale/solutions/solution/sip%2Bgateway%2Bservice.html

5.0 Wholesale Verizon SIP Gateway Service

http://www22.verizon.com/wholesale/solutions/solution/sip+gateway+service.html

http://www22.verizon.com/wholesale/solutions/solution/sip+gateway+service.html

6.0 Questions & Resources


Feel free to email questions to John or Kerry later if desired.

If you are interested in receiving email updates of the slide presentation and SIP Trunking resources please see Kerry before leaving to be added to our email distribution list.

6.0 Questions


Call or email us anytime with questions: SIP Technical Questions:

◦ John Downing◦ [email protected]◦ 613-435-1170

Professional Services related to SIP Deployments & Training Requirements:◦ Kerry Parnell◦ [email protected]◦ 613-799-6750

6.0 TrainingCity on your side




Review of equipment configurations Bandwidth requirements analysis Training:

◦ Course 784: VoIP Hands ON Workshop – 3 Days◦ Course 2004: SIP Hands ON Workshop – 2 Days

Professional Services


More Information TrainingCity Classes available on-site and as

Public Deliveries:◦ Course 2004: SIP Hands ON Workshop◦ Course 801: IPv6 Fundamentals◦ Course 802: DNSSEC Hands ON◦ Course 784: VoIP Hands ON Workshop

www.TrainingCity.com

Technology

SIP Trunking overview