Nortel Passport 15000 Hardware Description page 280

280 Chapter 4 Control and function processors
241-1501-200 5.2S2
Sparing a VSP3 at the far-end
The sparing of a VSP3 can be configured through the far-end equipment that
its gigabit Ethernet ports connect to. The intra-card sparing capability
protects the gigabit Ethernet ports from loss of traffic provided both ports are
configured for sparing and the far-end setup criteria are met. The inter-card
sparing capability protects the VSP cards through configured 1-for-one (1:1)
or one-for-n (1:n) sparing. However, during a switchover between cards,
traffic is lost. Combining the sparing of the cards and the gigabit ports
provides fast switchover for link failures and cold switchover for VSP3 cards.
The setup sparing for VSP3 cards involves the following.
• It depends on the hardware and software configuration of the far-end
equipment that the card connects to.
• The gigabit Ethernet port sparing is hot protection whereby the standby
port takes over without dropping active calls when a link failure occurs
on the active gigabit Ethernet port.
The criteria for the hardware sparing configurations are as follows:
• for one-for-one (1:1) or one-for-n (1:n) inter-card port sparing:
— the active and the standby cards reside in the same Passport shelf
— the cards are cabled to the same LAN (or VLAN), as are all devices
within an IP subnet
— the cards belong to the same protection group as designated by
software configuration
— the active and standby ports belong to the same IP subnet
— one card is configured as the Spare and each other card is configured
as a Main
— up to nn cards in the same Passport 15000 or 20000 shelf are
configured for sparing, where nn is 14 FP slots minus however many
TDM cards share the shelf, and the far-end supports sparing that
many VSP3s
• for one-for-one (1:1) intra-card port sparing:
— the VSP3 software has been configured to enable the sparing and
both are configured under the same logical processor (LP)