Ethernet Frames; Management Function; Figure 12 - Ptp 600 Series Bridge Layer Diagram - Motorola PTP 600 Series User Manual

4.3

Ethernet Frames

The PTP 600 series provides wireless Ethernet bridging between two fixed locations. To be
more precise, it forwards Ethernet frames as a two-port transparent heterogeneous
encapsulation bridge, meaning that each bridge forwards frames between two dissimilar
interfaces (Ethernet and wireless), encapsulating Ethernet MAC frames within a PTP MAC
frames for transmission at the wireless interface. A link consisting of a pair of back to back
bridges appears to the data network to be very similar to a standard two-port Ethernet bridge.
The PTP600 series provides two egress queues in each direction, classifying Ethernet frames
into one of the two prioritised queues based on inspection of the user priority field (802.1p) in
in a customer (IEEE802.1Q) VLAN tag or provider (IEEE802.1ad) VLAN tag. Untagged frames
receive a default priority. The queuing method is strict priority. The bridge does not implement
any VLAN functions for bridged frames apart from inspection of the priority field, and
consequently the bridge forwards tagged and untagged Ethernet frames regardless of VLAN
ID and without modification of any protocol header fields.
The PTP 600 series supports a maximum Ethernet frame size of 2000 bytes for bridged
traffic.
4.4

Management Function

The management function of the PTP 600 Series Bridge is logically equivalent to a separate
protocol stack with virtual point of attachment at the Ethernet interface. This is illustrated in
Figure 12.
Figure 12 – PTP 600 Series Bridge Layer Diagram
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4 Product Architecture