Session Initiation Protocol (SIP) has been around for many years and has become the de facto answer for both network trunking and endpoints, or “phones.” Vendors, analysts and perhaps even your IT department may position SIP as a panacea for the contact center. But what is it really, and why should you care?
SIP is a protocol standard for initiating and managing “sessions” or connections between point A and point B. It fits with “Voice over Internet Protocol” (VoIP), which is the way most voice communications works today, regardless of vendor or solution. But SIP isn’t just about voice—it can manage sessions for a variety of media (e.g., voice, video, chat), supporting the “omnichannel” contact center.
SIP enjoys strong market momentum, but a rising star is not reason enough to make significant changes when budgets and resources are limited. So let’s look at what compels companies to migrate to SIP beyond “the vendor made me do it.”
The biggest advantage of SIP may be in the trunking flexibility and agility. It is relatively quick and easy to set up, and you can buy what you want or need, as opposed to the increments of 23 in traditional PRI trunking. You can adjust capacity quickly, even on the fly, as it is software driven. Companies with seasonal or bursty traffic will find this very attractive, as they can procure capacity based on lower volume off-peak and pay for bursts when needed. And you can reroute quickly, offering a degree of resiliency that many seek. If business continuity/disaster recovery is a driver, companies will set up alternative paths and build that resiliency into the network configuration.
Beyond agility, lower cost can drive the transition from traditional trunking (e.g., PRI), but each company needs to make its own comparison. Some argue the cost benefits only come with compression of the voice, and if that is the case, you need to make sure quality isn’t compromised. In some cases, less hardware required, but look at the total cost of ownership for the configuration is important, as it’s not just about the trunks themselves, as SIP requires SBCs, proxy servers, etc. Some companies have network features such as percent allocation that may be replaced as a new network and configuration is put in place with SIP, so these costs should be considered as well.
For endpoints and architecture, the value is in choice and flexibility in endpoints. If the solution supports third-party SIP phones, you are more likely to have lower-cost options. SIP can also enable integration between dissimilar systems, including hybrid premise/cloud solutions.
While all this may sound attractive, nothing is perfect. Here are some risks to be aware of and mitigation methods to employ.
- Interoperability is not guaranteed. You need to select tested and approved options or bear the risk of failure.
- SIP is not inherently the “toll quality” voice that we experience on the traditional PSTN. Like all VoIP approaches, SIP is subject to performance issues, such as latency/delay, jitter and packet loss. You need to size your network to meet the business demands, and configure your routers to prioritize voice traffic. If you compress voice, perform testing and ongoing monitoring.
- SIP trunking is vulnerable to IP-based attacks, and SIP across the public internet is not encrypted. Your IT and security team will need to work with the vendors (system and carrier) to define an approach to protecting your infrastructure.
- You need in-house expertise to support SIP, or you can procure managed services from a provider. If your IT is interested in less responsibility, a provider that brings both the system and the network services may be appealing.
SIP will likely be a part of any solution in today’s market, and its momentum for trunking migration is strong. Choose your carrier(s) carefully, seeking Tier 1 redundant network and Service Level Agreements (SLAs) that show a commitment to solid, reliable service. Use proven, tested solutions and vendors, and allow time for testing with endpoints and trunking. Make thoughtful decisions about configuration: size appropriately, prioritize voice, and put appropriate security in place for your configuration and business needs. Then manage SIP well, keeping an eye on security, capacity, routing, performance and costs.
