Addressing audio latency or delay in phone calls

Updated by Bryan Jones


This document applies to all variants of the Telos VX phone systems.


Some customers complain of long latency during phone calls. This latency often results in your talent talking over the top of phone callers or vice versa. Some to the extent that the phone calls may seem unusable.

Historically this has been the result of 800 vanity numbers, which then get forwarded to a local SIP Trunk.


There is always some delay in phone calls. As a good example, use your cell phone and call someone else on their cell phone. Stand next to each other while you make this call.
Step 1

Test a local phone call. Use a Telos VSet and dial another extension on the system directly. Do not dial an "outside" line. We are looking to dial the internal (sometimes a four-digit) extension. This call should almost always be low enough latency to have a "normal" conversation. Sort of like the cell phone call referred to earlier.

Step 2

Make a test call but to the LOCAL phone number. Not the 800 number, but whatever number your 800 number is forwarded to. For example, 1-800-MYP-HONE might be forwarded to 216-241-7225. For this test, we want to call the 216-241-7225 number.

Step 3

Call your 800 number and note any delay.


You now know who to call about the problem.

Every time you forward a number, you will introduce some additional latency. We have seen cases where phone numbers are forwarded multiple times. The 800 number is forwarded to a local number, which is forwarded again to another local number. In most cases, having your 800 number ported directly to the provider of your SIP trunk provides the best performance.

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