In the RTN910 5.76.01.33 version, which is a native packet version, it is requested by costumer to configure E-LINE services in the FE ports with a bandwidth of 1554. First we tried to use U2000WebLCTV100R002C01SPC003 to create the E-LINE service with a 1554 MTU but as soon as you apply it changes the MTU value to 1500. Then we were using the T2000V200R007C03SPC003 to create the Ethernet service and it apparently changes the MTU value to the one set in
the configuration. Finally after some tests with the ethernet analyzer we found out that the MTU value configured in the service does no affect the traffic performance.
The conclusion was that the only value that affects the traffic of the Ethernet service is the Maximum frame length of the port, which by default is at 1620.
To limit the MTU of the ethernet services the only way is to change the Maximum frame length of the port
Due to the impossibility to change the MTU of the Ethernet service after it is created, we made some traffic tests, using an Ethernet analyzer.
1. Send streams upper than 1500 to check until what value of MTU the traffic passed without problem. The result was that despite the service was created with the U2000WebLCTV100R002C01SPC003 with a MTU of 1550, traffic of 1600
2. Then configured the E-LINE service with an 64 MTU value and send traffic with ethernet analyzer and with different MTU values beginning with 64 and increasing it by steps. The MTU values send were 64,128, 256, 1518, 1620. The result was that all the traffic
passed without packet loss.
Verify the Maximum frame length of the Ethernet port before send any traffic in order to guarantee no packet loss in the traffic passing through.