Chapter 1: Product description
Ethernet bridging
Page 1-14
Ethernet bridging
This section describes how the PTP 550 processes Ethernet data.
Ethernet ports
The PTP 550 Series ODU has two Ethernet ports:
•
Main PSU: The Main PSU port provides a copper Ethernet interface for 100BASE-TX and
1000BASE-T, and accepts power from the AC Power Injector to the ODU (802.3at).
•
SFP: The SFP port is a small format pluggable receptacle accepting copper or optical plug-
in modules supplied as part of the SFP module kit.
Data network
Transparent Ethernet service
The PTP 550 Series provides an Ethernet service between one of the Ethernet ports at a local
ODU and one of the Ethernet ports at an associated remote ODU.
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 in the customer network is 1538 bytes.
Layer two control protocols
The Data Service in the PTP 550 Series 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 PTP 550 Series does not generate or respond to any L2CP traffic.
Protocol model
Ethernet bridging behavior at each end of the wireless link is equivalent to a two-port,
managed, transparent MAC bridge.
