Ace ACE-3205, Инструкция по установке и эксплуатации

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Appendix E Encapsulation over PSN Installation and Operation Manual
E-12 4BTDM Service Encapsulation ACE-3105, ACE-3205 Ver. 5.2
Table E-11. AAL5-SDU Control Word Parameters
Parameter Name Purpose
Reserved Reserved for future use; assigned with 0 value.
T Transport type bit. If set to 1, the packet contains
an ATM admin cell. If not set, the PDU contains
an AAL5 payload.
E EFCI bit. Set to 1 if the EFCI bit of one or more
cells in the AAL5 CPCS-SDU is set also to 1.
Otherwise, it is set to 0.
C CLP bit. Set to 1 if the CLP bit of one or more cells
in the AAL5 CPCS-SDU is set also to 1. Otherwise,
it is set to 0.
U Command/response field bit. Set to 0.
Sequence number A 16 bits, unsigned and rounded number that can
be used to guarantee ordered packet delivery.
E.4 TDM Service Encapsulation
TDM traffic can be encapsulated over PSN in two modes:
•
CESoPSN – CES (Circuit Emulation Services) over PSN
• SAToP – Structure-Agnostic over Packet.
Accordingly, the TDM Control Word frame is structured differently for each
encapsulation mode. For the TDM payload illustration, see
TDM Payload .
CESoPSN Control Word
The following figure illustrates the structure of the CESoPSN Control Word:
0 0 0 0 L R M FRG LEN (6 bits)
Sequence number (2 bytes)
Figure E-17. CESoPSN Control Word Structure
Table E-12. CESoPSN Control Word Parameters
Parameter Name Purpose
Bits 0–3 Structure bits that their value must be zero
L If set, indicates that the TDM data carried in the
payload in invalid due to a TDM circuit failure
R Remote receive failure (PSN RDI) on the PSN side