User's Guide

PTP 250 User Guide Ethernet bridging
phn-2182_003v004 (Oct 2011)
UNDER DEVELOPMENT
1-23
Ethernet bridging
This section describes how the PTP 250 controls Ethernet data in the customer and
management networks.
Customer network
Transparent Ethernet service
The PTP 250 provides an Ethernet service between the Ethernet port at a local ODU and
the Ethernet port at an associated remote ODU. The Ethernet service is based on
conventional layer two transparent bridging, and is equivalent to the Ethernet Private Line
(EPL) service defined by the Metro Ethernet Forum (MEF).
The service is transparent to untagged frames, standard VLAN frames, priority-tagged
frames, provider bridged frames, and provider backbone bridged frames. In each case, the
service preserves MAC addresses, VLAN ID, Ethernet priority and Ethernet payload in the
forwarded frame. The maximum frame size for bridged frames is 2000 octets.
Layer two control protocols
The PTP 250 is transparent to layer two control protocols (L2CP) including:
• Spanning tree protocol (STP), rapid spanning tree protocol (RSTP)
• Multiple spanning tree protocol (MSTP)
• Link aggregation control protocol (LACP)
• Link OAM, IEEE 802.3ah
• Port authentication, IEEE 802.1X
• Ethernet local management interface (E-LMI), ITU-T Q.933.
• Link layer discovery protocol (LLDP)
• Multiple registration protocol (MRP)
• Generic attribute registration protocol (GARP)
The system does not generate or respond to any L2CP traffic.