How to Solve Cisco IP Phone Voice Quality Issues. The step by step guide.

How to solve Cisco IP Phone Voice Quality Issues

You get a call from a user stating that they have experienced poor voice quality issues with their Cisco IP phone.
Your mind goes numb, your palms get sweaty, and your eyes glaze over. What do you do? Where do you start? It’s so much easier to deal with problems where something stops working completely, rather than trying to resolve an intermittent fault such as bad voice quality.

Why are poor voice quality issues so difficult to tackle?
It’s usually because there is a myriad of different causes, and the methodology to investigate those causes is not always readily or intuitively clear. For voice troubleshooters, it is important to have a battle plan in place to quickly zero in on causes of voice degradation and to diagnose, identify, and resolve them as quickly as possible.

This article will focus on this battle plan so that you can identify the problem quickly, and determine the first troubleshooting steps, which are often the most difficult to decide upon.

Continue reading How to Solve Cisco IP Phone Voice Quality Issues. The step by step guide.

Cisco Voice Translation Rules. The Only Guide You’ll Ever Need.

Cisco Voice Translation Rules

Hey UC Pros! The need to interoperate across organizational and logical borders with different numbering requirements exists since the very beginning of the digital telephony.
Whether you interconnect with a SIP ITSP or your own legacy PBX, you will likely need to manipulate digits you exchange on both ends.
In Cisco IOS (and IOS-XE later) running either CUBE or Voice Gateway, Voice Translation Rules and Profiles come to a play to help you get things done.

In this article, we are going to demonstrate how this powerful feature works in general and how it applies to most common interoperability scenarios in real UC world.

Let’s begin.

Continue reading Cisco Voice Translation Rules. The Only Guide You’ll Ever Need.

SIP Response Codes Explained

Why don’t we start with some trivia?
Did you know that SIP response codes are based on HTTP/1.1 response 404-not-foundcodes?

Actually, SIP response codes are the extent of the original HTTP ones and even define a new class with more response codes. I’ll let you know which one when we get to it.

That said, not all of the HTTP codes are relevant and mapped to SIP response codes, so if you know some HTTP, don’t expect to find them all in this list.
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Cisco SIP Gateway configuration: The Ultimate Guide

Connecting the Cisco IOS Voice Gateway to CUCM via SIP has been the preferred way to do it in the past couple of years.

The slowly dying H323 protocol (ISDN based) is not being developed anymore while SIP (HTTP based) became the industry standard for VoIP. So whenever PSTN connection is implemented via an IOS Voice Gateway, the choice should be really between SIP & MGCP.

This is how it’s done, step by step, using SIP.

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CUCM SIP Call Flow Troubleshooting

SIP Call FlowThere is no way around it,
finding the SIP call flow is the first thing you have to do when you are facing a SIP call failure.

Because first of all, you have to understand whether this is a call routing problem or signaling/media compatibility issue.
SIP call flow helps you understand just that, and in a lot of cases, you can pinpoint the problem just from looking at the SIP call flow.

Continue reading CUCM SIP Call Flow Troubleshooting