Contents

Introduction

Prerequisites

Requirements

Components Used

Background Information

Test Ports

For Windows

Related Information

Introduction

This document describes steps to test TCP SIP traffic ports in order to troubleshoot when supported Devices for Webex Calling are present.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

- Understand of your Webex Calling environment and architecture

- Have read the Port Reference Information for Webex Calling

- Basic troubleshoot on device register issues.

- Have run the CSCAN tool Webex calling offers Use CScan to Test Webex Calling Network Quality

Components Used

This document is not restricted to specific software and hardware versions.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Background Information

This document describes a basic way to troubleshoot and test whether you have access to the Webex Calling Signaling Session Initiation Protocol (SIP) ports.

In some cases, devices fail to register, and show a offline or issues status on Control Hub.

You need a packet capture so you can investigate whether the device the expected SIP flow to register:

In a packet capture, if successful, it appears similar to the next image:

The red box indicates that the TCP connection was established.

In the next image is an example of when a the TCP connection is not established:

Here, only TCP SYN is seen on the capture, so the device is not able to open the TCP connection.

Note: When you encounter this sort of issue, you need to investigate why this is blocked. In some cases, it is blocked on the Firewall side, however, further investigation needs to be done.

There are some steps that you can do to validate TCP connections from your Windows/MAC.

Test Ports

For Windows

Open the power shell, and use these commands:

tnc 10.119.57.136  -p 8934

tnc 10.119.56.136  -p 8934

Additionally, use  ipconfig  to check the source:

Note: The IP addresses shown here are Webex Calling Session Border Controller (SBC).

Go to Terminal and use the next commands:

nmap -sV -p 8934 10.119.57.136

nmap -sV -p 8934 10.119.56.136

Additionally, use  ipconfig  to check the source:

Related Information

- Use CScan to Test Webex Calling Network Quality

- Cisco Technical Support & Downloads