User`s manual
Chapter 1 Overview
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When using VC-3: the maximum of two virtually concatenated groups per
MUXpro. For example, a group using two VC-3s can be used to carry the
maximum traffic load of a 100Base-TX Ethernet port.
When using VC-12: the 63 VC-12s can be divided as required to create
up to 6 groups. For example, a group using 5 VC-12 can be used to carry
the full traffic load of a 10BaseT Ethernet port over SDH.
It is allowed to build virtually concatenated groups using different types of
VCs: for example, when using VC-12 to carry E1 traffic, one or two groups can use
VC-3s, and the remaining bandwidth (17 VC-12) can be assigned to one or two
additional virtually concatenated groups.
Route the groups. The routing is defined by any means of mapping (mapping
is the selection of specific VCs to be used to carry each group, the number
needed to carry the bandwidth selected in Step 1 showing above).
This operation creates the trails that are needed to connect the local users to
remote locations via the SDH network.
1.6.4.3 Support for LCAS
Each virtually concatenated group with two or more VCs can be configured to
support LCAS. With LCAS, the capability of a virtually concatenated group can be
decreased when one of the VCs get failed; when the failure no longer appear, the
group will automatically recover and return to the normal capability.
The user can configure diverse LCAS protocol parameters, and can also specify a
minimum number of VCs for the group capacity; if the number of VCs decreases
below this minimum, an alarm will be generated.
1.6.4.4 GFP Multiplexer Function
Virtual concatenation provides the means to transport payloads at rates that differ
from those are available in the standard SDH hierarchy. Therefore, virtual
concatenation is always used by the MUXpro to carry the LAN traffic (unless a
single VC is used).
Although virtual concatenation leads to improved utilization of available bandwidth,
better utilization would be achieved by taking into consideration the statistical
allocation of traffic generated by multiple Ethernet nodes, and reserving bandwidth
only for the average load. The capability is provided by the MUXpro GFP