Traffic Management in the Network
13-7
Traffic
Management in the
Network
Figure 13-2 below shows a network scenario, where two 7600 Cards,
denoted by source station and destination station are found with an ATM
cloud between them. The shaded area between the stations represents a
VCC connection over which a data flow and an RM-cell flow takes place
as shown. The traffic management is performed as follows:
1
A forward RM cell is sent at regular intervals on each VC from the source
end station.
2
The EFCI bit is set in data cells by the ATM switch when congestion is
found along the VC path.
3
The destination end station recognizes the EFCI bit and the backward RM
cell congestion indicator bit is set.
4
The backward RM cell is returned to the source end station through the
ATM switch.
5
VC traffic flow is altered based on information in the RM cell.
Figure 13-2
Traffic Management control steps
abtthgde.book Page 7 Tuesday, June 23, 1998 10:29 AM