Specifications

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Cisco MGX 8850 (PXM45) and MGX 8950 Software Configuration Guide
Release 3, Part Number 78-14788-01 Rev. C0, January 2004
Chapter 1 Preparing for Configuration
Planning for Card and Line Redundancy
• The switch ends of each Y-cable must connect to corresponding ports. For example, the cable
connected to line 2 on the active lower bay back card must also connect to line 2 on the standby lower
bay back card.
• Optical Y-cables must use single-mode fiber (SMF) cable, not multimode fiber (MMF).
• The remote end of the standalone line can connect to a standalone AXSM/FRSM-12 card or a
redundant AXSM/FRSM-12 card set with a standalone line. (It cannot connect to an
AXSM/FRSM-12 APS port.)
Planning Redundant AXSM Configurations with Redundant Lines
Maximum fault tolerance is achieved when redundant AXSM cards are used with redundant APS lines.
In this configuration, fault tolerance is provided for the front card and for the combination of the back
card and the communication line. If the active line or the back card to which it is connected fails,
communications traffic is rerouted through the backup line and the back card to which it is connected.
Note APS is supported only on AXSM cards.
Figure 1-10 shows how a redundant AXSM card connects to redundant APS lines.
Figure 1-10 Redundant AXSM Configuration with Redundant Lines
Figure 1-10 shows two complete sets of AXSM cards. Each port in each card slot connects to an
independent line. If the front card in the active card set fails, the standby card set becomes active and
continues to support calls over the shared communication line. If the working line fails, communications
are rerouted through the protection line for that port.
When planning a redundant AXSM configuration with redundant lines, consider the following:
• The redundant AXSM cards must be placed in adjacent slots. They can be installed in slots 1 though
6 and slots 9 through 14.
• The AXSM card sets must be identical. You cannot pair unmatching cards such as an AXSM T3/E3
card and an AXSM OC-3 card.
AXSM front cards AXSM back cards
1
2
45057
Midplane
1
2
1
2
1
2
Working line 1.1
Protection line 1.1
Protection line 1.2
Working line 1.2
Working line 2.1
Protection line 2.1
Protection line 2.2
Working line 2.2