Alcatel-Lucent 7705 Service Manual page 157

7705 SAR OS Services Guide
Table 21: Control Word Bit Descriptions (Continued)
Bit(s)
M
(Modifier)
FRG
LEN
Sequence number
Description
The M bits are a 2-bit modifier field. For SAToP, M is set to 00
as per RFC 4553. For CESoPSN, M is set according to RFC
5086, summarized as follows:
• When L bit = 0, and
M = 00 – Normal conditions
M = 01 – Reserved for future use
M = 10 – RDI condition for the attachment circuit (AC)
M = 11 – Reserved for CESoPSN
• When L bit = 1, and
M = 00 – TDM data is invalid
M = 01 – Reserved for future use
M = 10 – Reserved for future use
M = 11 – Reserved for future use
The FRG bits in the CESoPSN control word are set to 00.
The LEN bits (bits 10 to 15) carry the length of the CESoPSN
packet (defined as the size of the CESoPSN header plus the
payload size) if it is less than 64 bytes, and set to 0 otherwise.
The sequence number is used to provide the common PW
sequencing function as well as detection of lost packets.
VLL Services
Page 157