Parameter: Packet Network: Type of Service
(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 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| 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