Why You Need SIP Trunking – The Basics

If you have an IP-ready PBX or are thinking about purchasing a new PBX, this might be the right time to think about SIP Trunking.

SIP (Session Initiation Protocol) is a standard used around the world for communicating voice or video between devices and software. A SIP trunk is an IP connection that establishes a SIP communications link connecting your business to the Publicly Switched Telephony Network (PSTN).

SIP Trunking enables voice communications and features such as Microsoft Lync’s Enterprise Voice functionality. It helps businesses become more competitive by dramatically reducing telephony communication costs and increasing flexibility and the speed of response to customers.

If you are thinking about implementing a unified communications platform such as Microsoft Lync, then you also need to think about implementing SIP Trunking.

To learn more about Microsoft Lync and its great collaborative features, register for our  upcoming webinar hosted by our team of Microsoft Professionals who will discuss:

  • Best practices and recommendations learned from our extensive experience designing and managing hundreds of unified communication implementations
  • Answers to common questions around Lync, IM and Presence
  • The how-to’s of integrating Lync with legacy PBXs
  • The Basics of SIP Trunking –a primer for the future
The webinar will be followed by a Q&A so you will have an opportunity to discuss your unique challenges with our Microsoft experts. Register Now!

Why use SIP Trunking?

In the past, we all used two separate structures for voice and data communication. As Voice over IP and Unified Communications evolved, more and more organizations opted for the benefits of using one flexible IP SIP connection to support both voice and data.

Here are some of the biggest benefits of SIP Trunking we’ve seen:

Costs: When data and voice are combined, you no longer pay for telecom providers and services. All connections can be centralized, reducing the needs for separate lines to branch offices. Long distance charges are usually greatly reduced as ”over the Internet” tends to be much cheaper than traditional telephone lines.

This has a major impact on Contact Centers for example, who gain significant savings with a switch to SIP Trunking. Long distance charges decrease while call center staff gain productivity benefits when using Microsoft Lync IM, presence and unified conferencing (which includes video, audio, and web conferencing). For more information about IM and Presence, read our recent post 4 Questions Customers Ask Us About Lync, IM and Presence.

Scalability: As SIP is a virtual connection, additional lines can be added or reduced easily as demands change, unlike traditional circuit based lines such as T1’s which can take several weeks to provision.

Stability: SIP may offer better reliability than the traditional telecom “pipe” as SIP automatically reroutes to new paths, should there be an outage on the system, so high availability is maintained. In addition, should a disaster occur, it’s much easier to reroute calls to a different system, reducing the chances of service disruptions. In fact, some SIP providers offer re-routing of inbound calls to mobile devices in the event of major outages meaning less missed calls.

User Experience:  SIP Trunking offers the ability to easily provision DID (Direct Inward Dial) numbers from any area code regardless of location enabling businesses and users to be able to make and receive calls from the area of their choice regardless of their location. (ie. Living in Toronto and handling the Vancouver sales territory)

The Challenges

Like every deployment there are always challenges to be dealt with as you transition to a new system– here are some of the common issues we’ve seen working with customers.

  • Building the Foundation: SIP interacts with multiple systems including storage, security and applications so it is crucial to have an integration plan ready before you begin any implementation. We often recommend customers work through our UC Roadmap Service to clarify some of the complex integration issues they need to address. The roadmap helps define an existing environment, establish functional requirements, and provides solution options to help in the decision making process. For more information about requirements planning, be sure to read our post 3 Steps for a Successful Lync Deployment.
  • Call Quality can become an issue if not considered and addressed properly given that voice traffic could be contending with other internet based data traffic. It may be necessary to provision a separate connection for SIP Trunks or to work with your provider to ensure Quality of Service (QoS) is enabled for voice traffic.
  • Maintaining high availability and resiliency on all sites whether remote or centralized. Ensuring the best availability and resiliency on trunks while maintaining cost effectiveness can become challenging. For example, deploying a decentralizedSIP Trunking strategy may provide maximum resiliency however likely results in higher per trunk costs.
  • Security is another concern for many organizations since SIP Trunks are data connections from another external source whereas with traditional circuit based connections this concern did not exist. With the appropriate planning, security concerns can be addressed as well as ensuring that the appropriate hardware is in place to do this properly.
  • Will there be a co-existence period? If you are phasing in SIP Trunking, this will involve a co-existence period where you will maintain your current circuit based PSTN connection, meaning you will need to carefully consider how these circuits are retired in the most efficient manner
  • Inbound Trunks with SLAs. Most organizations require high availability for their telephony system so it is important to work with your SIP Trunking Provider to understand what SLA’s are in place to deliver this service to your organization.

What’s the impact on IT/Telecom Staff?

As voice and data converge, staff dedicated to voice services may be impacted. Our experience is that this is a great time to encourage them to update their training and education in the features and functions that need to be supported in Lync. Voice skills are still required in a Lync/SIP Trunking environment and having those skills updated could prove very valuable for both the employer and staff.

Planning is key for a successful deployment

SIP Technologies can have a major impact on your entire infrastructure, so it is very important to have a structured plan first to ensure you have a clear understanding of the existing environment and capabilities you need. Let us know if you’d like more information about how our Roadmap Service can help you adopt and maximize the benefits of SIP.

In addition, check out our Microsoft Lync 2010 Unified Collaboration (Voice) Proof of Concept service which can help you evaluate the platform and capture business requirements.  Please let us know if you’d like more information about Roadmap Services or the Proof of Concept offering or feel free to leave a comment or question below and we’ll respond as soon as we can.

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About Dino Caputo

Dino has achieved several professional accreditations including his MCSE and CCNA, and is also a Certified Novell Engineer and Administrator.