Table 9: Rising Edge Sample When Video Flow Starts - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - QUALITY OF SERVICE CONFIGURATION GUIDE 2010-09-22 Configuration Manual

Starting Video Flow
Copyright © 2010, Juniper Networks, Inc.
Table 9 on page 91 lists the dynamic rate when the video flow is turned on for the five
classes of simple shared shaper variables. Results vary because the amount of video
measured in the first rising period is random, in the range 0–4 Mbps non-inclusive.

Table 9: Rising Edge Sample When Video Flow Starts

Period of Dynamic Rate, in Kbps
Control 1 2
Most 1 5 0 0 0 13080
liberal
Liberal 1 5 0 0 0 9542
Moderate 1 5 0 0 0 6510
Conservative 1 5 0 0 0 6022
Most – –
conservative
In this example, a liberal maximum VOQL value is ineffective because the 15 Mbps
shared-shaping rate is much higher than the 4 Mbps video rate. The video rate divided
by the shared shaping rate is 26.6 percent, so any value higher than this has no effect.
NOTE: The rates in this example represent approximate egress-queue
enqueue rates on an Ethernet line module; therefore, there is no ATM SAR or
downstream devices are not used. More liberal configurations can be
inappropriate when there might be queuing between the scheduler and the
destination. VLAN queuing is used, and saturation rates are offered.
The most liberal case heavily reduces VOQL and changes of rate, leading to a shared
shaper that quickly converges. The conservative configuration overreacts to VOQL and
the change of rate, and converges very slowly.
Figure 25 on page 92 shows a graph of the dynamic rate when the video flow starts.
Chapter 11: Configuring Variables in the Simple Shared Shaping Algorithm
3 4 5 6
11000 11000 11000 11000
8880 10470 10867 10972
5606 8303 9651 10329
1604 3953 5714 7038
– – – –
7 8 9 10
11000 11000 11000 11000
10979 10994 10998 10994
10628 10814 10967 10953
7978 8733 9300 9735
– – – –
91