Parameter: Packet Network: Type of Service
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(Redirected from TOS)
Value to store in the TOS (Type Of Service) field of the IP header of RTP packets.
The most recent usage of this field is a six-bit Differentiated Services Code Point (DSCP) and a two-bit Explicit Congestion Notification (ECN).
| 0 | 1 | 2 | 3 | 4 | 5 | 7 | 6 |
|---|---|---|---|---|---|---|---|
| DSCP field | ECN field | ||||||
For example, if a TOS value of 144 is used, the DSCP tag will be 36 (if ECN field is not used). Some examples:
| TOS Value | DSCP Value |
|---|---|
| 0 | 0 |
| 32 | 8 |
| 40 | 10 |
| 56 | 14 |
| 72 | 18 |
| 88 | 22 |
| 96 | 24 |
| 112 | 28 |
| 136 | 34 |
| 144 | 36 |
| 152 | 38 |
| 160 | 40 |
| 184 | 46 |
| 192 | 48 |
| 224 | 56 |
DSCP <=> IP Precedence Conversion Table
| DSCP Name | DS Field Value (Dec) | IP Precedence (Description) |
|---|---|---|
| CS0 | 0 | 0: Best Effort |
| CS1, AF11-13 | 8,10,12,14 | 1: Priority |
| CS2, AF21-23 | 16,18,20,22 | 2: Immediate |
| CS3, AF31-33 | 24,26,28,30 | 3: Flash - mainly used for voice signaling |
| CS4, AF41-43 | 32,34,36,38 | 4: Flash Override |
| CS5,EF | 40,46 | 5: Critical - mainly used for voice RTP |
| CS6 | 48 | 6: Internetwork Control |
| CS7 | 56 | 7: Network Control |
Wikipedia link: Type of Service
