Comtech EF Data CDM-760 - Manual (Page 409)

Appendix K Revision 2
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
K–9
K.4.2.3.2 Example 2
• Select Min/Max as the QoS Mode.
• Configure each queue with minimum bandwidth (Min BW), maximum bandwidth (Max BW),
and weight as shown in Table K-6.
• The total available bandwidth is 30000 kbps.
Calculate each individual allocated kbps.
Table K-6. Example 2 – QoS Classification
Queue Min BW (kbps) Max BW (kbps)
Delta Max BW
(Max-Min)
(kbps)
Weight Allowed BW
Q1 2000 4000 2000 9 – –
Q2 4000 8000 4000 8 – –
Q3 6000 16000 8000 7 – –
Q4 8000 8000 0 6 – –
Total ► 20000 40000 14000 30 30000
Table K-7. Example 2 Solution – Calculated BW Allocation
Queue
1 st Round 2 nd round N th round Final
kbps Weight Given Leftover Weight Given Leftover Weight Given Leftover
Q1 9 3750 1750 – – – – – – – – – – – – 2000
Q2 8 3334 – – 8 934 268 – – – – – – 4000
Q3 7 2916 – – 7 816 – – 7 268 – – 4000
Q4 – – – – – – – – – – – – – – – – – – – –
Total ► 24 10000 1750 15 268 7 0 0 10000
Table K-7 displays the solution for Example 2.
Step 1 – The sum of all queues’ minimum bandwidth (20000 kbps + total available bandwidth) =
30000 kbps. Once the sum of all minimums are met, there is a remainder of 10000 kbps overage
available for use.
The overage bandwidth is distributed to all non-served maximum bandwidth queues. In this
example, only Q1, Q2, and Q3 still have unmet maximum bandwidth.
Since Q4’s minimum and maximum bandwidths are the same, Q4 is therefore excluded from the
remaining overage distribution.
The remaining total weights are (9+8+7) = 24.
Step 2 – Calculate each bandwidth share, based on total weights (24) and bandwidth availability
(10000 kbps) after the minimum is served (20000 kbps).