Motorola T1/E1 manual Vlan Support, Round‐Trip Packet Delay, Alarms

Canopy T1/E1 Multiplexer	September 2004
	T1/E1 Multiplexer FPGA Version 3.4

1.5.6VLAN Support

The Canopy T1/E1 Multiplexer fully supports customer VLAN traffic. The Canopy T1/E1 Multiplexer has an increased maximum Ethernet packet size of 1600 bytes. Typically, the maximum packet size is 1518 bytes for Ethernet traffic, however VLAN traffic adds an extra 4 bytes for the VLAN tag as in the 802.1Q protocol. In addition, some manufacturers, such as Cisco, have proprietary VLAN applications that result in extra long Ethernet packets.

1.5.7Round‐Trip Packet Delay

The one-directional delay between the two T1/E1 endpoints would be approximately 20 milliseconds. This delay does not include any delay added by Canopy Backhaul Modules. The Ethernet throughput delay is the time required for one Ethernet packet to pass through the LAN port of the Canopy T1/E1 Multiplexer. The maximum one-directional delay for an Ethernet packet of size 1518 Bytes is approximately 240 microseconds, excluding the delay that Canopy BH modules introduce.

1.5.8Alarms

The Canopy T1/E1 Multiplexer supports the Alarm Indication Signal (AIS). It is sent under 2 conditions: a loss of incoming T1/E1 signal (in which case AIS is sent out to the far end and the same for the other end losing T1/E1 signal) and a loss of BH link (in which case the AIS is sent in both directions).

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