Cisco Cisco IOS Software Release 12.0(23)S

Using VC bundles, you can create differentiated service by flexibly distributing IP precedence levels 
over the different VC bundle members. You can map a single precedence level or a range of levels to 
each discrete VC in the bundle, thereby enabling individual VCs in the bundle to carry packets marked 
with different precedence levels. You can use WRED to further differentiate service across traffic that 
has different IP precedences, but that uses the same VC in a bundle.

Here are some benefits of using VC bundle management:

Provides flexible configuration of different traffic shaping parameters such as UBR or VBR with 
different parameters for traffic with different precedence levels.

Provides flexible VC management within a VC bundle on permanent virtual circuit (PVC) failure, 
also referred to as VC bumping, which allows traffic assigned to a failed VC to be redirected to an 
alternate VC within the VC bundle.

Allows a combination of VC bundle and per-VC WRED and per-VC MDRR.

The following restrictions apply for VC bundle management:

VC bundle management on the 8-Port OC-3 STM-1 ATM line card is supported on point-to-point 
subinterfaces only. VC bundle management on the 8-Port OC-3 STM-1 ATM line card is not 
supported on either point-to-multipoint subinterfaces or main interfaces.

On a point-to-point subinterface, you can configure either one regular PVC or one VC bundle, which 
can contain up to eight VC bundle members, but not both.

VC bundle management on the 8-Port OC-3 STM-1 ATM line card is supported for PVCs only, not 
switched virtual circuits (SVCs).

Only aal5snap and aal5mux encapsulation types are supported for VC bundles.

Multiprotocol Label Switching (MPLS)

Layer 3 quality-of-service (QoS)

Weighted Random Early Detection (WRED)

Modified Deficient Round Robin (MDRR)

Low Latency Queueing (LLQ)

See the 

 section for a list of documents that describe these features and 

technologies.