7 Common SIP Trunking Mistakes to Avoid

December 31, 2019

So you’ve started your SIP Trunking reselling business – congratulations! This can be a very profitable venture, but there are a few pitfalls you need to avoid. Let’s review some of the common mistakes and how you can prevent them. 

1-Insufficient Bandwidth 

While the savings with SIP Trunking are ordinarily quite substantial, there are some cases where investment in additional Internet bandwidth is necessary. This situation occurs more often in smaller businesses that do not yet have business-class internet service. While this is becoming less of an issue, checking into your customer’s bandwidth and type of service before installation can help avoid unexpected expenses. 

If you want to know how much bandwidth is needed to support high-quality calls, this simple equation can help:

85 Kbps X Number of Concurrent Calls = Required Bandwidth

An estimate of how many concurrent calls you can have with your given bandwidth is given below:

  • 1 Call = 100Kbps
  • 5 Calls = 500Kbps
  • 10 Calls = 1Mbps
  • 15 Calls = 1.5Mbps
  • 20 Calls = 2Mbps

2-The Wrong Number of SIP Channels

Figuring out how many calls your customer’s business may receive at one time is critical because every call requires a SIP channel. Choosing the right number of channels is the best way to help your customers save money vs. what they would pay with a traditional PRI solution.

To get an accurate idea of the number of channels your client needs, look at the number of outbound and inbound calls their business needs to be able to make at any one time. Their records regarding their phone calls may help you to determine these figures.

However, if they can’t provide this kind of data, you can make an assumption based on the number of employees at their location and the nature of their work. 

Let say the company has ten employees. Generally speaking, they may have between three and four simultaneous phone calls. Of course, this differs if their business model is intensively call based. For example, they have a lot of inside sales or are a call center. 

Generally speaking, higher call volume requires more bandwidth and more SIP channels. 

3-Overlooking e911

On landlines, we take for granted that a call to 911 will go to the correct public safety answering point and that vital location information will be transmitted to emergency dispatchers.

When using SIP, the e911 service must be subscribed to and configured or calls may be misdirected and location information won’t be sent. Make sure that every physical location for each of your customers has at least one enhanced DID and that the location information is properly setup.

4-Moving Fax Machines and Alarms to SIP

Even though moving your phones, fax machines, and alarms from an analog network, all to SIP may save your customers money, moving fax and alarm systems to your network can cause unforeseen issues.

As a best practice, your customers should keep the alarm system running on a dedicated analog line provided by the phone company. They may also wish to continue using an analog fax machine or consider an electronic fax replacement. This service allows your clients to send and receive faxes from their computers, doing away with the dedicated fax machine and analog line.

So, as much as you may be tempted to offer a complete switch over, do your customer a favor and keep their alarm system and analog fax on traditional phone lines.

5-Ignoring QoS (Quality of Service)

QoS is a router setting that prioritizes voice traffic over data. When it is not properly configured, high-bandwidth data activities like streaming video or downloading large files can result in poor audio quality for phone calls. 

Make sure to help your customers configure their router to ensure quality of service. Most business-class routers have this capability. If your client’s router doesn’t have this feature, be sure to recommend an upgrade.

6-Inadequate Endpoint Testing 

SIP trunks can be used with IP phones, mobile devices, and browser-based softphones. It’s important to test each endpoint that your client plans to use.

Connection issues with an IP phone mean its unable to connect to the SIP trunk server. Softphones that connect through a PC may experience this due to the computer’s firewall blocking SIP traffic. 

7-Toll-Fraud Mistakes

While all of the benefits of SIP trunking are worth the switch, moving to internet-based connectivity does introduce additional risks in terms of toll-fraud. There are a couple of things you can do to help your client avoid this costly problem.

First, make sure you choose to resell a SIP trunking platform that has automated features to reduce the risk of toll-fraud. Next, make sure your client understands the risk. Advise them to insist on strong credentials for all web applications, phone logins, voicemail PINS and so forth. Finally, suggest that they only allow outbound calls to the countries in which they are actively doing business.

Finding the Right Balance

With SIP Trunking, it’s often finding the right balance that makes for a satisfied customer. So, take your time and review their business, calling history, systems before diving in with a one for all solution. The right answer is usually found in the details. As a SIPTRUNK reseller, you have many resources available to you. Still have questions? Let us know!