Bandwidth Calculation

This section provides formulas for calculating the bandwidth required for DCN communication between a GNE and an NMS.

Bandwidth for communication between the NMS and GNEs must be large enough for the NMS to run commands and for NEs to report information. The bandwidth depends on the network scale. Generally the committed information rate (CIR) and peak information rate (PIR) are used to calculate the required bandwidth. The formulas for calculating the CIR and PIR are as follows:

• CIR
  • N>56: CIR = 2048 + (N - 56) x 0.5 kbit/s
  • N<=56: CIR = 2 Mbit/s
• PIR
  • N>56: PIR = 10240k + (N - 56) x 5 kbit/s
  • N<=56: PIR = 10 Mbit/s

NOTE:

In the formulas, N is the number of DCN equivalent subracks.

Table 1 Conversion between physical NEs and DCN equivalent subracks

Physical NE	Number of DCN Equivalent Subracks
	In an Electrical Subrack	In an Optical Subrack
NE with one OptiX OSN 3800 subrack	1	0.5
NE with one OptiX OSN 6800 subrack	1	0.5
NE with one OptiX OSN 8800 T16 subrack	1	0.5
NE with one OptiX OSN 8800 T32 subrack	1.5	1
NE with one OptiX OSN 8800 T64 subrack	2	1
NE with one OptiX OSN 8800 Platform Subrack	N/A	0.5
An electrical subrack consists of cross-connect boards, OTU boards, tributary boards, line boards, or protection boards. An optical subrack consists of OADM boards, multiplexer boards, demultiplexer boards, optical amplifier boards, OSC boards, optical spectrum analyzing boards, regeneration boards, or OLP boards (used in optical line protection).

CIR indicates the permitted rate at which information is sent in normal situations and is expressed in bit/s.

PIR is also expressed in bit/s and must be greater than or equal to CIR.

The recommended user bandwidth is equal to the PIR or a larger value. If this cannot be satisfied, the bandwidth must be at least larger than the CIR.