Zhone zNID-GPON-2402 Configuration Manual page 212

Configuration
212
zNID 24xx Series Configuration Guide
Table 58: CoS value to priority mapping
CoS Value Priority Queue
5 High
6 Critical
7 Critical
Packets which require the highest throughput or are sensitive to latency (the
amount of time between received packets) should be in higher priority queues.
Normally video and voice are more sensitive to throughput and latency issues.
Precedence
IP packets have a ToS byte in their headers that contains information about
relative priority. The IP Precedence field contains a 3-bit priority designation.
Most normal traffic has an IP Precedence value of zero. Higher values in this
field indicate that traffic is more important and that it requires special treatment.
IP Precedence values greater than 5 are reserved for network functions.
The format of the ToS byte:
Table 59: Precedence values
Precedence Values
0 (Routine)
32 (Priority)
64 (Immediate)
96 (Flash)
128 (Flash Override)
160 (Critical)
192 (Internetwork Control)
224 (Network Control)
Note: Data is prioritized using only the Precedence bits, not the
entire Diffserv field.
Priority Method
WRR 16/8/4 (weight = 16)
Strict priority
Strict priority
Priority Queue Priority Method
Low WRR 16/8/4 (weight = 4)
Low WRR 16/8/4 (weight = 4)
Med WRR 16/8/4 (weight = 8)
Med WRR 16/8/4 (weight = 8)
Med WRR 16/8/4 (weight = 16)
High WRR 16/8/4 (weight = 16)
Critical Strict priority
Critical Strict priority