Troubleshooting Your IP Phone Setup with a Hosted VoIP Provider

Updated: December 09, 2010

All calls go in 2 directions, inbound and outbound. Unlike the old-school copper-wire POTS calls, VoIP calls are connected through the internet. As such, when troubleshooting an IP phone that won't register or receive inbound calls, one must consider the local network, router/firewall, and internet connection.

With POTS, the connection is a dedicated circuit between the customer and the phone carrier. With internet calling, made possible by Session Initiation Protocol (SIP), the connection in between is shared. And, the dial tone on SIP phones is simply a user familiarity feature on the phones. While a dial tone does indicate a local network connection, it's not the same indication as a POTS line; just because there's a dial tone doesn't mean you can successfully make or received calls.

Successful calling on hosted VoIP service requires the call information to transit your LAN, your router/firewall, and the internet with as few issues as possible. If your phone alerts that it can't make a network connection, then there is likely an issue is on your local network.

A few tips:

SIP only works through 1 NAT; multiple routers will cause calls and registrations to fail. This is why in our OnSIP Knowledgebase, we review hardware that supports SIP communication.

The same goes for inbound calls: there has to be a clear path to the phones for calls to ring and connect. If there are any connectivity issues between our servers and your phone, they will affect call quality, possibly causing garbled words (due to dropped packets), sound delay, and distortion. If you experience any of these symptoms, you can check your packet loss by pinging us at sip.onsip.com. A 1% packet loss will cause audio problems.

Sometimes, internet connectivity issues are obvious. If you notice that your web pages are loading slowly or not at all and your call quality is that of 2 cans and a piece of string, then it's time to call your ISP and get them to fix the squirrel damage to the wires in your neighborhood possible. However, just because web pages are loading fine and the call quality is poor, doesn't mean it's not an internet connectivity issue. Check a speed check webpage like speedtest.org to see if you are getting the speed you pay for.

Another issue some experience with setting up a VoIP network is calls that go straight to voice mail without ringing. In our experience with OnSIP, this means we (the provider) can't get your phone to respond to our invites. To troubleshoot, make sure that your router allows UDP, which SIP uses.

Featured Research
  • Work Smarter Not Harder with Business Intelligence

    While this may have been true at one time, the days of BI requiring a dedicated team of experts to implement are over. Self-service solutions are making it possible for everyone, including small, local businesses, to easily implement BI in their decision making process. more

  • Best Practices for Contact Center Quality Assurance

    A contact center often brings about a prospect’s first real-time interaction with your company. As such, if it’s not a positive one, they’ll likely look elsewhere for help. With 69% of Americans more inclined to recommend a company to friends and family after a positive customer service experience, you’ll need to exceed expectations on the following fronts. more

  • The New 2017 Phone Systems Comparison Guide

    It was a painstaking process, but to help B2B companies start 2017 off on the right foot, we recently compiled a comparative list of the top 34 business phone vendors in the world. In one, easy-to-reference location, we’ve neatly outlined the information you need. more

  • How to Make Your Contact Center More Efficient

    There’s a very good chance that your contact center is underperforming. With consumer preferences continuously changing, strategies that were once effective now result in too many unsatisfied customers. Fixing this problem involves reviewing your current procedures and optimizing them to drive better results. more

  • 8 Common Pain Points UC Eliminates

    Many businesses rely on a collection of communication tools that they adopt to address specific needs as they arise. This strategy may seem to work in the beginning, but eventually will lead to a system that is cumbersome to use, difficult to explain to new hires, expensive, and effective in some areas, but full of gaps. more