363-206-295
Maintenance Description
9-24
Issue 1
December 1997
Dual Ring Interworking (DRI) Path Protection
Scheme
9
Interconnected rings or DRI is a topology that connects two rings together at two
geographically separate nodes to provide an alternate route if a catastrophic
failure occurs at one of the interconnecting nodes. See Section 2, "Applications,"
for more information on DRI. Figure 9-8 shows DRI path protection switching.
Note that the upper ring could be an FT-2000 OC-48 Lightwave System
bidirectional line switched ring. In the receive direction, a DRI node that passes a
signal between rings performs two steps:
1.
VT1.5 and/or STS-1 signals to be passed between rings are "dropped and
continued." This means the signal is dropped at that node to the Function
Unit and simultaneously copied into the OC-3/OC-12 signal in the outgoing
direction of the same ring rotation.
2.
The VT1.5 and/or STS-1 signal that was dropped in Step 1 and the
corresponding VT1.5 and/or STS-1 signal incoming from the other ring
direction are compared, and the signal with the highest quality is selected
as in single ring topologies.
In the transmit direction, a DRI node feeds VT1.5 or STS-1 signals in the direction
opposite to the "continue" portion of the drop and continue signal (Step 1
previously) to only one rotation of the ring as shown in Figure 9-8.
This routing is to only one rotation or "disabled bridge" as distinguished from how
an ordinary path switched ring bridges incoming low-speed traffic onto both
rotations.
The drop and continue disabled bridge routing necessary for DRI is established
with a cross-connection command.
Содержание DDM-2000 OC-12
Страница 1: ...363 206 295 Issue 1 December 1997 DDM 2000 OC 12 Multiplexer Release 7 0 User Service Manual Volume I ...
Страница 37: ...Tables xxxviii Issue 1 December 1997 A A SONET Overview A 1 SONET Payloads A 18 A 2 SONET Transport Rates A 19 ...
Страница 506: ...INS PROG 8 of 8 Page INS PROG COMMANDS RELATED rtrv eqpt rtrv ne OC 12 DDM 2000 1997 December 1 Issue 11 89 ...
Страница 528: ...RTRV ATTR ALM 2 of 2 Page RTRV ATTR ALM COMMANDS RELATED set attr alm OC 12 DDM 2000 1997 December 1 Issue 11 111 ...
Страница 565: ...RTRV OC3 3 of 3 Page RTRV OC3 COMMANDS RELATED rtrv sync 11 148 1997 December 1 Issue OC 12 DDM 2000 ...
Страница 664: ...SET FEAT 3 of 3 Page SET FEAT COMMANDS RELATED rtrv feat OC 12 DDM 2000 1997 December 1 Issue 11 247 ...
Страница 766: ... Ctl T TOGGLE 2 of 2 Page Ctl T TOGGLE COMMANDS RELATED logout rlgn OC 12 DDM 2000 1997 December 1 Issue 11 349 ...
Страница 847: ...Multiplexer OC 12 DDM 2000 7 Release TARP TOP Manual User Service II Volume 363 206 295 1 Issue 1997 December ...
Страница 867: ...363 206 295 TOP Maintenance and Operation BLANK LEFT INTENTIONALLY PAGE THIS 12 1997 December 1 Issue ...
Страница 1145: ...Order Circuit 363 206 295 NTP 029 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1146: ...Order Circuit 363 206 295 NTP 030 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1182: ...Turnup System 363 206 295 NTP 033 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1243: ...Clearing Trouble 363 206 295 TAP 107 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1393: ...363 206 295 DLP 513 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1394: ...363 206 295 DLP 514 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1456: ...363 206 295 DLP 523 7 of 7 Page 1997 December 1 Issue OC 12 via Access Broadcast Video for Cross connections of Example 4 Figure ...
Страница 1465: ...DLP 525 363 206 295 1997 December 1 Issue 6 of 2 Page Schematic Ring Virtual ATM Sample 1 Figure ...
Страница 1469: ...DLP 525 363 206 295 1997 December 1 Issue 6 of 6 Page Ring Virtual ATM OC 12 DDM 2000 for Cross connections of Example 4 Figure ...
Страница 1565: ...363 206 295 DLP 543 6 of 5 Page 1997 December 1 Issue Network Broadcast Video of Test Transmission 2 Figure ...
Страница 1566: ...DLP 543 363 206 295 1997 December 1 Issue 6 of 6 Page Network Ring Virtual ATM of Test Transmission 3 Figure ...