How to change the MTU of ShoreTel Switches

[[email protected]]

I have tried my best to find a cfg file or CLI command that will allow me to modify the MTU size of a ShoreTel switch however I have come up short. ShoreTel level 1 TAC says there is no way to do it.

So I will ask here, has anyone been able to modify the default value of 1500 for the MTU of the ShoreTel switches?

Thanks,
Chris Rouse

[luckycharms]

The largest packet that is allowed on the network layer for Ethernet is a 1500 byte packet. This is the max for the rest of the internet, so this is protocol based, which is why ShoreTel won't provide support.

[[email protected]]

Well ShoreTel not only supports the modification of the MTU size on the following product but also shows how to configure it.
With this in mind I thought there might be a way to configure it on the older switches but there may not be any Known way to modify the value.
I just hoped there might be a curious soul out there that had accomplished this goal before.

SIP BRI 8: (Documentation)

http://support.shoretel.com/products/voice_switches/downloads/shoregear_sip-bri_8_admin_guide.pdf

Thank you for taken the time to respond and provide some input.

[ejsearle]

Did you ever find the registry entry to change the MTU? I can't seem to find it anywhere.

[ShoreTel_Dave]

Default mtu is 1400 bytes which should be good for most people. You can shrink it if required, but you might make things worse.
If you break it, then remove the setting from the registry again, remember that the value in the registry must end with a full stop . character.

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Shoreline Teleworks\Telephony Management Server\Settings
Key Name= SwitchDebug
Add this parameter and an appropriate value to the end of the string before the . terminating character:

ether_mtu_size 1350

ShoreTel_Dave is not affiliated with ShoreTel.