Description:

This guide describes the various stages of analysis that can help identify the cause of only one-sided sound transmission.

Analysis Steps (Basis)

1. Does the error always or only sporadically occur?
2. Is a user/phone affected by this error or all users/phones?
3. Which side of the conversation can not be heard?
4. Have there been any changes to the existing network structure or firewall?
5. Which provider type is in use (SIP or ISDN)?

Analysis Steps (Logfiles)

In the text-based log files of STARFACE, problems with audio transmission are very difficult to analyze. The simplest and fastest way of analysis is to make a TCPdump and evaluate it with the program "Wireshark". In addition, it is essential to check the firewall or the entire network structure regarding the forwarding of the ports 10.000 to 20.000 (see also Overview of Port Usage of the STARFACE).

Analysis via TCPdump

First, a TCPdump must be created on the STARFACE that records a conversation during which no audio data was transmitted (see also Enable TCPdump on the STARFACE oder System Status of the STARFACE). The following key data are required for the analysis with the "Wireshark" program:

1. Exact time of conversation
2. Type of call (e.g., from internal to external mobile number)
3. Call number to which has been called
4. Call number from which has been called
5. IP address of the STARFACE
6. IP address of all participating phones
7. Type of provider (ISDN or SIP)