Marconi OMS 1200
Technical Product Description
221 02-ZAP 701 25/1 Rev C 2006-08-04
© Ericsson AB 2006
03PHB00004AAV-CUA
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Figure 7-8: MSP Protection with STM-4/16 Core Card
PROTECTION
WORKER
1
OMS1200 - STM 4/16 CORE
LINE B
LINE A
2
TERMINAL MUX
7.4.3 K1/K2
Protocols
Two different signalling protocols are used to control MSP - the ITU-T/ETSI Protocol
(G.783, G.841, ETS 300 417-3-1, ETS 300 746) and the Siemens Proprietary
Protocol. Both employ two bytes for signalling located in the SOH - K1 and K2.
The choice of protocol is a configurable option on a per protection section basis at the
LCT/LCTS.
7.4.3.1 ITU-T/ETSI
Standard K1/K2 Protocols
The K1/K2 protocol described in the standards referred to above is used to send
requests for switching. This is used in 1+1 bi-directional and unidirectional modes. The
1+1 K1, K2 protocol mechanism compatible with 1:N network architectures, is used.
The tail end duplicates traffic and sends the K1 and K2 to the far end informing it of
the switch to the protection channel. The head end responds by duplicating traffic to
the protection card and sends a reverse request with the bridged channel in the K2.
The tail end sees that the transmitted K1 and the received K2 match and switches its
receive selector. The head end sees that the transmitted K1 and the received K2
match and switches its receive selector as well.