I recently had a requirement to change the MTU on an AudioCodes E-SBC to match that of an upstream routing device. The MTU change cannot be made via the GUI and must be performed via the CLI, if you don’t have access to supporting documentation this can be quite difficult to locate.
1. Using Putty or a similar application connect to your device using Telnet as the connectivity method.
2. When prompted for authentication enter the devices user name and password.
3. Once authenticated type the word “enable” and when prompted enter the enable password, if you do not know this or it doesn’t match the password you utilised to initially authenticate, try the devices default password.
4. Once in enable mode enter the following commands, each on a new line, in order to change the MTU. Note the MTU listed is an example and should be adjusted to match that of the upstream routing equipment. The listed interface in this example is the one that is connected to the routing device, to identify what interface name you need to use run “show running-config” and review the output until you see the interface name that matches the assigned IP address to the WAN interface for example.
interface gigabitethernet 0/0
That’s it all done, don’t forget to burn the change to flash once complete.