
Bridging
The process to convert a frame to forward that is in the internal format into
the output format varies on the media type, the encapsulation, and the type
of frame to send:
For a PVC with VC multiplexing encapsulation, the frame transmission
process inserts the heading Pad field (0x0000). No FCS is added.
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•
•
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For a PVC with LLC/SNAP encapsulation, the frame transmission
process inserts the LLC/SNAP header (LLC+OUI+PId+Pad fields)
without ending FCS.
For an Ethernet interface, the frame transmission process inserts the
preamble, start of frame delimiter, and the ending FCS.
If the bridge is VLAN-aware and the frame must be sent untagged, the
802.1Q tag is removed.
3.2.10
Example: Ethernet-to-ATM – no VLAN – ATM VC Multiplexing
3.2.11
Example: ATM-to-Ethernet – no VLAN – ATM LLC/SNAP
Encapsulation
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1553-LZY 214 2655 C 2004-11-24