> For the complete documentation index, see [llms.txt](https://prosbcdocs.telcobridges.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://prosbcdocs.telcobridges.com/telecom-references/sip-and-voip/voip-ethernet-capture.md). # VoIP Ethernet Capture The [Tmedia](https://telcobridges.com/media-gateways/products/tmedia-gateways/) product can configure one of its VoIP Ethernet ports to do [Port Mirroring](http://en.wikipedia.org/wiki/Port_mirroring). This is useful when investigating RTP, Codecs or IP Tones issues. #### Preparing the Tmedia for capture (enable ports mirroring) * If the traffic to be captured is on a 802.1Q VLAN and the [Tctrl](https://github.com/telcobridges-main/tmedia-wiki/tree/main/reference/concepts/tctrl/README.md) version is >= 2.8, an IP interface with the 'MANAGEMENT' service must be created through the Web Portal. The IP interface must be assigned to a virtual port that is assigned to the capture port and uses the 802.1Q VLAN ID that is targeted by the capture. * Access the [Tmedia](https://telcobridges.com/media-gateways/products/tmedia-gateways/) unit using SSH. * Access the telecom baseboard from the [Tmedia](https://telcobridges.com/media-gateways/products/tmedia-gateways/) using telnet. telnet 172.31.1.1 * Type in the mv88eMonitor command to get the list of ports on the unit: mv88eMonitor * A list (such as the one below) should appear: Port Mapping: PortDesc : eth0 eth1 voip0 voip1 mspeedsw1 mspeedsw2 fpga0 fpga1 host cpu PortNumber : 0 1 2 3 4 5 6 7 8 9 PortMask : 0x1 0x2 0x4 0x8 0x10 0x20 0x40 0x80 0x100 0x200 * The 'PortNumber' is the **destination** port for the capture. * If the traffic is to be captured on the **internal host** of the TMG unit, use the number below the **host** port (in the above example, 8). * If the traffic is to be captured on an **external host** (laptop, PC, or specialized equipment), choose the number below the desired target port (for example, 0 for eth0). * The 'PortMask' is the **source** mask for the capture. On the above example, traffic going through the voip0 port would be captured using the 0x4 mask. * Use the mv88eMonitor command in order to mirror traffic as desired. Here is the syntax: mv88eMonitor * The 'IngressPortMask' is the mask used for capturing traffic that is sent to the TMG. * The 'EgressPortMask' is the mask used for capturing traffic that is sent from the TMG. * The 'PortNumber' is where the captured traffic should be mirrored to. * The 'TimeoutInSeconds' is the time the mirror operation is active before being automatically stopped. * Here is an example to mirror all the voip0 traffic to a TMG3200's internal host, for 60 seconds: mv88eMonitor 0x4 0x4 8 60 * Here is an example to mirror the incoming voip0 traffic on a TMG3200 to an external host connected to the eth1 port: mv88eMonitor 0x4 0 1 60 #### Start the capture * Exit the telecom baseboard's shell (type "exit") * If the capture is to be done on an external host, use a tool such as 'Wireshark' to capture and analyze the mirrored traffic. * When configuring a port as a mirror, it is important to connect that Ethernet port directly to a host (like a laptop). Otherwise, it could cause issues such as an Ethernet loop. * If capturing 802.1Q tagged traffic, make sure the receiving equipment is actually configured to process 802.1Q tagged traffic. * If the capture is to be done on the TMG's internal host: * Use the [**tbinfo**](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/operations/get-product-type/README.md) command to find out which product is currently used. * Use the following table to know on which Linux interface to capture the traffic: | TMG800 | TMG3200 | 802.1Q capture | | --------- | -------- | ------------------------------------------------------ | | **mgmt0** | **int0** | **vlanXXXX**, where XXXX is the VLAN ID (e.g. vlan333) | * Use the "tcpdump" tool to capture mirrored packets: tcpdump -i mgmt0 -s 1500 -w capture\_file.cap * To capture 802.1Q tagged traffic, use the correct VLAN interface: tcpdump -i vlan333 -s 1500 -w capture\_file.cap #### Stop the Capture When you're ready, stop the capture by * pressing control-C on the shell that was running tcpdump command * Access the telecom baseboard from the [Tmedia](https://telcobridges.com/media-gateways/products/tmedia-gateways/) using telnet. telnet 172.31.1.1 * Stop the capture mv88eMonitor 0 0 0 #### Download the Capture To download the capture, use SSH secure copy ("sftp") to the Tmedia management port. This can be done on Windows using tools like Filezilla. ### Procedure * [VoIP Ethernet Capture for v3.2](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/configuration/tmedia-tdev-and-tsig-web-portal-3-2-troubleshooting/README.md#voip-ethernet-capture) * [VoIP Ethernet Capture for v3.0](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/configuration/tmedia-tdev-and-tsig-web-portal-3-0-troubleshooting/README.md#voip-ethernet-capture) * [VoIP Ethernet Capture for v2.10](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/configuration/tmedia-tdev-and-tsig-web-portal-2-10-troubleshooting/README.md#voip-ethernet-capture) * [VoIP Ethernet Capture for v2.9](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/configuration/web-portal-2-9-troubleshooting/README.md#voip-ethernet-capture) * [VoIP Ethernet Capture for v2.8](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/configuration/web-portal-2-8-troubleshooting/README.md#voip-ethernet-capture) * [VoIP Ethernet Capture for v2.7](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/configuration/tmedia-tsig-and-tdev-web-portal-2-7-tutorial-guide/README.md#voip-ethernet-capture) --- # Agent Instructions This documentation is published with GitBook. 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