Network bandwidth

Bandwidth requirements

In order to effectively manage the network, the NFM-P must have access to sufficient bandwidth between the NFM-P server(s),the NFM-P auxiliary(s), and the network elements.

This bandwidth will be used to carry the management traffic between the NFM-P and the network element. The following table describes the bandwidth requirements for a particular network element.

Table 4-8: NFM-P server to network bandwidth requirements

Network element example

Bandwidth requirement from NFM-P server(s) to the network element

7950 XRS

2-4 Mbps

7750 SR-12E (fully loaded)

2 Mbps

7750 SR-12 (fully loaded)

2 Mbps

7750 SR-2s

2 Mbps

7750 SR-a4

1 Mbps

7750 SR-c12 (fully loaded)

600 Kbps

7450 ESS-7 (fully loaded)

1 Mbps

7450 ESS-1

200 Kbps

7705 SAR (fully loaded)

200-400 Kbps

7250 IXR-6 / 7250 IXR-R4 / 7250 IXR-R6 / 7250 IXR-R6d / 7250 IXR-R6dl / 7250 IXR-x

800-1000 Kbps

7250 IXR-e / 7250 IXR-e2

300 Kbps

7210 SAS-E, 7210 SAS-M, 7210 SAS-K

200-300 Kbps

7210 SAS-D, 7210 SAS-X, 7210 SAS-T, 7210 SAS-R, 7210 SAS-Mxp, 7210 SAS-Sx

500-600 Kbps

7701 CPAA / vCPAA

250 Kbps

9500 MPR / Wavence SM

200 Kbps

OmniSwitch 6250, 6350, 6400, 6450, 6465, 6560, 6850, 6865, 9000 Series

300 Kbps

OmniSwitch 6860, 6860E, 6860N, 6900, 10K

400 Kbps

1830 VWM OSU

400 Kbps

Details on the bandwidth requirements

The recommended bandwidth described above is a conservative figure that is meant to ensure that the performance of NFM-P and its ability to manage successfully each network element will not be affected by unusual network conditions.

Specifically, the bandwidth recommendation ensures that the NFM-P can fully discover (or resynchronize) all of the objects contained in the network element, within a reasonable amount of time, varying heavily based upon the specific network element type and configuration.

The following are the main operations that result in significant amounts of information being exchanged between the NFM-P and the network elements. These factors are therefore the principal contributors to the bandwidth requirements:

For some network elements, the management of the NE includes methods other than the standard MIB/SNMP management, for example, web-based tools. These network elements may require additional bandwidth above the bandwidth levels stated in Table 4-8, NFM-P server to network bandwidth requirements.

Possible consequences of insufficient bandwidth

In situations where there is less than the recommended bandwidth between the NFM-P and the network element, the following are possible consequences:

Determining total bandwidth requirements for NFM-P managed networks

The amount of bandwidth required for each of the network elements should be obtained from Table 4-8, NFM-P server to network bandwidth requirements.

The total amount of bandwidth that is required for the NFM-P to manage the complete network will vary based on the topology of the infrastructure that is used to carry the management traffic. From the perspective of NFM-P, there must be sufficient bandwidth (according to Table 4-8, NFM-P server to network bandwidth requirements) between itself and each of the NEs it manages.

In cases where the management traffic is carried over physical point-to-point links between the NFM-P server and the NFM-P auxiliary network and each of the network elements, sufficient bandwidth must be reserved on the physical links. The NFM-P server complex can simultaneously communicate to several NEs for the following functions:

It would be rare for all of the operations listed above to be performed simultaneously; therefore, in normal circumstances, the NFM-P can communicate with at least 20 to 30 NEs simultaneously. This minimum can increase to 60 or 70 NEs on a 16 CPU core NFM-P server station. For networks of over 1000 NEs or where an NFM-P auxiliary statistics collector is being used, that number should be increased by 20 to 30 NEs. A higher bandwidth may be required under special cases where above average data is attempted to be transferred between the NFM-P and the network elements. For example, large statistics files, NE backups, or software images.