Pos Functions - NEC UPD98413 User Manual

3.3 POS FUNCTIONS

The µ PD98413 can map POS packets into a SONET/SDH payload.
according to HDLC frame processing. The following is an overview of POS packet processing.
On the sending end, the µ PD98413 performs HDLC processing on the packet data entered from the POS interface
and maps it as POS packets into a SONET payload, inserting a flag sequence (7Eh) between packets.
On the receiving end, the µ PD98413 extracts POS packets from the SONET frame payload entered from the line
interface, based on the flag sequence (7Eh). It then performs HDLC processing on the POS packets and sends them
to the POS interface.
The mapping of POS packets into a SONET payload and the POS packet format are shown below.
SOH
CHAPTER 3 FUNCTIONAL OUTLINE
Figure 3-20. Mapping of POS Packets
7E 7E
7E 7E
7E
7E 7E
POH Fixed stuff
PRELIMINARY
POS packet processing is performed
7E
POS packet 7E
POS packet 7E
Payload
7E
7E
7E POS packet
NEC confidential and Proprietary
7E
7E
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