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12-3
Cisco SCE 2000 and SCE 1000 Software Configuration Guide
OL-7827-12
Chapter 12 Value Added Services (VAS) Traffic Forwarding
How VAS Traffic Forwarding Works
When VAS traffic forwarding is enabled (
Figure 12-1
), in addition to all its basic functions, the SCA BB
application classifies each flow as either a VAS flow or as a standard flow (non-VAS flow).
Flows that were classified to a VAS service get the usual SCA BB service, as well as being forwarded
to the VAS servers for additional service.
Logically, “VAS engine” is upstream of “SCA engine”, meaning upstream traffic is first processed by
the SCA BB application, downstream is first processed by the VAS server.
Routing the traffic to the VAS servers is done by using VLAN tags.
Figure 12-1
Typical VAS Traffic Forwarding Installation
Important information:
•
A single SCE platform can support up to eight VAS servers.
•
A maximum of 512 SCE platforms can be connected.
•
The same VAS server may be used by more than one SCE platform.
•
The VAS traffic forwarding feature is supported on the SCE 2000 4xGBE platform only.
Note
When working in VAS mode, the SCE performance envelope might be up to 50% lower than in normal
operation mode. The exact performance envelope is specific to the traffic mix in the customer network
and should be sized in advance.
The following sections provide a more detailed description of how VAS traffic forwarding works.
LINK RX
Cisco SCE 20
00
Series
4xGBE
TX
RX
MM
TX
LINK RX TX
RX
MM
TX
LINK RX TX
RX
MM
TX
LINK RX TX
RX
MM
TX
GBE-1
SUB
LINE
NET
PWR B STAT
US
PWR A
BYPASS
10/100/
1000
LINK/
ACTIVE
10/100/
1000
LINK/
ACTIVE
GBE-2
SUB LINE/CA
SCADE NET
AUX
CONSOLE
MNG 2
MNG 1
VAS Servers
SCE
Subscribers
Network
157202