Possible consequences of insufficient bandwidth
In situations where there is less than the recommended bandwidth between the 5620 SAM
and the network element, the following are possible consequences:
•
The length of time required to perform a network element discovery will increase
•
The length of time required to perform a SNMP poll of the network element will
increase
•
The length of time required to retrieve statistics from the network element will
increase
•
The proportion of SNMP traps that will not reach 5620 SAM because of congestion
will increase. This is significant since 5620 SAM will detect it has missed traps from
the network element and will result in 5620 SAM performing additional SNMP
polling to retrieve the missing information. This will result in additional data being
transferred, which will increase the bandwidth requirements, possibly exacerbating
the situation.
Determining total bandwidth requirements for 5620 SAM-managed networks
The amount of bandwidth required for each of the network elements should be obtained
from
Table 5-12, “5620 SAM Server to network bandwidth requirements” (p. 5-12)
.
The total amount of bandwidth that is required for 5620 SAM to manage the complete
network will vary based on the topology of the infrastructure that is used to carry the
management traffic. From 5620 SAM’s perspective, there must be sufficient bandwidth
(as per
Table 5-12, “5620 SAM Server to network bandwidth requirements” (p. 5-12)
)
between itself and each of the network elements that is under management.
In cases where the management traffic is carried over physical point-to-point links
between the 5620 SAM Server and 5620 SAM Auxiliary network and each of the network
elements, sufficient bandwidth must be reserved on the physical links. The 5620 SAM
Server complex can simultaneously communicate to several NEs for the following
functions:
•
NE Discovery, NE Resync, Resyncing for Trap Processing
•
NE Backups, NE Software Downloading, and sending configurations to NEs
•
Collecting Performance Statistics
•
Collecting Accounting Statistics
•
Initiating STM Tests on NEs
•
Retrieve STM Test Results - also via FTP
•
NE Reachability checks and NE trap gap checks
Rarely are all of the above performed simultaneously so it is recommended to assume for
link aggregation points that SAM can communicate with a minimum of 20-30 NEs
simultaneously – this can increase to 60-70 NEs on a 16 CPU core 5620 SAM Server
workstation. For Networks of over 1,000 NEs or where a SAM Auxiliary Statistics
Network requirements
5620 SAM bandwidth requirements for communicating with
network elements
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5620 SAM
3HE-09809-AAAG-TQZZA 13.0 R7
Issue 1
December 2015
5-15
