Datasheet

Page 6 of 11

Advanced Bandwidth Management Feature

Advanced bandwidth management mechanisms in the ATM

OC-3 network modules architectureallow forthe support of

bursty,client/server trafﬁcwhile supporting applicationsthat

require guaranteed or best-effort service. The ATM OC-3

network modules’ bandwidth management capabilities

exceed those of existing ATM interface in midrange routers.

Thisnew feature providestheability to keeptrackof the

bandwidth used by a VC on a per-interface basis. It prevents

the oversubscription of the ATM link and is conﬁgurable by

the user. Bandwidth Manager for CBR is turned on

automatically for all interfaces supporting CBR. All other

ATM service categories need to be manually conﬁgured. The

total bandwidth allocated on the interface is tracked by

aggregating the values speciﬁed below for each VC.

Whenever a new VC is requested, the requested rate is

checked against the available rate to ensure the available

bandwidth is not exceeded.

ATM Layer Management

Operations and management (OAM) cells are used for ATM

layer end-to-end link management messages. This is

necessary to ensure that the remote connection is alive and

functioning. Support is provided for both OAM F4 and F5

ﬂows. During segmentation the OAM cells have the highest

priority, and will be transmitted ahead of other queued up

data. During reassembly, the OAM trafﬁc will be routed to a

global OAM receive buffer pool of 512 64-byte buffers.

Orderability, Availability, Software, and Memory Requirements

Table 2 ATM- OC-3 Network Modules for Cisco 3600 Series Routers

Note: no additional DRAM memory is required to support the OC-3 ATM network modules, other than Cisco IOS Release

12.0(3)T Plus speciﬁed minimum memory requirements. More detailed information of 12.0(3)T feature set memory requirements

are available in the Cisco 3600 series 12.0(3)T Product Speciﬁc Release Notes.

Part Number Descriptions

Orderable/Available Date

IOS Requirement

NM-1A-OC3MM (=) Single-Port ATM OC-3c/STM1 Multimode Network Module March 1999 12.0(3)T Plus feature sets

NM-1A-OC3SMI (=) Single-Port ATM OC-3c/STM1 Single-Mode, Intermediate Reach Network Module March 1999 12.0(3)T Plus feature sets

NM-1A-OC3SMl (=) Single-Port ATM OC-3c/STM1 Single-Mode, Long-Reach Network Module March 1999 12.0(3)T Plus feature sets