Transition Networks
S4224 Web User Guide
33558 Rev. C
Page 212 of 669
1+1 Port Protection
Two ports on a unit are paired with two ports on a Peer-Unit to create a Working-Protecting pair between
the units. After the initialization of Protection Group, Both links are active and transmit data. When a link-
failure is detected, the Protecting Link is used to continue data transmission.
1:1 Port Protection
Two ports on a Unit a paired with two ports on a Peer-Unit to create a Working-Protecting pair between
the units. After the initialization of Protection Group only the Working Flow is active and both end points of
the Protecting Flow are blocked for data transmission. When a link failure is detected on the Working
Link, a Protection switch is initiated and the Protecting Link will now be used for active data exchange.
1:N Port Protection
Above sections listed a strict 1:1 redundancy. However, there are two points to consider when setting up
redundancy:
Strict pair redundancy reduces the actual number of usable ports to n/2 which may not be the
best use of available resources.
The probability of all or most links failing at the same time is very low.
Considering the above, a 1:N Port Protection scheme is also possible.
Multiple 1:1 protection groups are configured but the same Protecting Link is chosen in all the groups as a
fall-back for the Working Link. Assuming that any of the Working Link fails, a Protection switch to this
Protecting Link can be made and traffic can be restored.
Once the faulty Working Link is restored, Automatic (Revertive)/Manual Protection switch can be done to
make the Protection Link available to other Groups.
It must be noted that if one of the Working Link is down and a Protection switch is executed, all the other
Working Links (with same Protection Link as back-up) go into an administrative hold-mode. This means
that if there is a Link Failure in one of these links, there will be no switchover to a Protecting Link.
Messages
Invalid command for this configuration
