ATIS T1.105.01 : 2000

Foreword
1 Scope
2 Normative references
3 Abbreviations
4 Definitions and classifications
5 Architectures
6 Linear APS
7 Ring APS
8 Nested APS
Tables
1 Byte K2 functions for linear APS
2 Byte K1 (bits 1-4) APS request codes for linear APS
3 Byte K1 (bits 5-8) switch action channel requests for
    linear APS
4 Byte K1 functions for ring APS
5 Byte K2 functions for ring APS
6 Relationships between K2 bit 5 and K1 bit 1-4 for rings
7 Byte K1 and K2 values sourced in the Idle state for rings
8 Byte K1 and K2 values sourced by a ring node in the
    switching state
9 SD-P and SF-P co-existing with ring switches on the same
    span
10 Hierarchy of conditions for service selection
Figures
1 Isolated node signaling (signaling states prior to B
    and D establishing a ring bridge and switch)
2 BLSR interconnection with opposite-side routing
3 Example of ring interworking
4 Interconnection between two BLSRs
5 Example of drop-and-continue
6 Effects of demand pattern on capacity of bidirectional
    line-switched rings
7 Example of circuit routing in failure state for a ring
    switch
8 Two-fiber bidirectional line-switched ring
9 Four-fiber bidirectional line-switched ring
10 Conceptual representation of a ring topology map
11 Conceptual representation of node squelch and RIP tables
12 Bridge and switch in a two-fiber bidirectional ring
13 Example of potential for misconnection
14 Conceptual representation and example of a NUT table
15 Four-fiber BLSR - Node failure
16 Four-fiber BLSR with VT access - Node failure
17 Two- or four-fiber BLSR - Bidirectional SF(ring)
18 VT squelching example
19 Four-fiber BLSR - Unidirectional failure (span) on working
20 Two- or four-fiber BLSR - Unidirectional SF(ring)
21 Two- or four-fiber BLSR - Unidirectional SD(ring)
22 Four-fiber BLSR - Node failure on a ring with VT access
    and Extra Traffic
23 Four-fiber BLSR - Unidirectional signal fail (span)
    preempting a unidirectional signal fail (ring) on
    adjacent spans
24 Ring interconnection example
25 Interconnection of a BLSR and UPSR
26 BLSR ring interconnection - Link failure restoral with
    secondary circuit on protection and an intermediate node
    (enhanced operation at secondary node)
27 BLSR ring interconnection - Normal operation with
    secondary circuit on protection
28 BLSR ring interconnection - Primary node failure restoral
    with secondary circuit on protection
29 BLSR ring interconnection - Primary node failure restoral
    with secondary circuit on protection - Case with
    intermediate node between the primary and secondary nodes
30 Potential misconnection when two drop-and-continue RIP
    circuits are set up to use the same time slot and share
    the same primary node
31 Dual transmit ring interworking (relieved congestion P - S)
32 Dual transmit ring interworking (improved bandwidth
    efficiency)
33 BLSR interconnection with dual transmit and same-side
    routing
34 BLSR interconnection with dual transmit and opposite-side
    routing
35 Unidirectional circuit squelching example where the
    failure is in the direction of the unidirectional circuit
36 Unidirectional circuit squelching example where the
    failure is in the opposite direction from the
    unidirectional circuit
37 Bidirectional circuit squelching example
38 Multiply dropped unidirectional circuit example
39 Multiply dropped unidirectional circuit squelching
    example where the failure is in the direction of the
    unidirectional circuit
40 Multiply dropped unidirectional circuit squelching
    example where the failure is in the opposite direction
    from the unidirectional circuit
41 Multiply sourced unidirectional circuit example
42 Multiply sourced unidirectional circuit squelching
    example where the failure is in the direction of the
    unidirectional circuit
43 Multiply sourced unidirectional circuit squelching
    example where the failure is in the opposite direction
    from the unidirectional circuit
44 Example with two unidirectional circuits
Annexes
A 1:n bidirectional switching example
B Definition of PDI
C Bibliography

Establishes specifications for the automatic protection switching of optical facilities using the optical interface standard detailed in the American National Standard for Telecommunications SONET (Synchronous Optical Network) - Basic Description including Multiplex Structures Rates and Formats ANSI T1.105-1995. This standard defines the contents of the Automatic Protection Switching (APS) bytes within the SONET signal.