Physical phones have the advantage of being able to mark their own ethernet traffic with DSCP\ToS marks to classify the traffic as higher priority than normal "best effort" ethernet traffic. For routers that support reading and prioritizing traffic based on these marks, it is the most reliable way to enable QoS for phones.
Polycom phones provisioned to our service will utilize the ToS mark 5 for both SIP and RTP audio traffic. This can be overridden to the more modern DSCP mark per account if required.
Most all other supported phones utilize the DSCP mark AF31 (26) for SIP traffic, and EF (46) for RTP audio traffic. This allows you to give slightly higher priority to audio traffic than SIP to prevent things like large sets of BLF updates from taking priority over an audio stream, while both have higher priority than normal best effort traffic.
Below is a reference chart of all DSCP \ Tos marks:
| DSCP Class | DSCP (bin) | DSCP (hex) | DSCP (dec) | ToS (dec) | ToS (hex) | ToS (bin) | ToS Prec. (bin) | ToS Prec. (dec) | ToS Delay Flag | ToS Throghput Flag | ToS Reliability Flag | TOS String Format |
| none | 000000 | 0×00 | 0 | 0 | 0×00 | 00000000 | 000 | 0 | 0 | 0 | 0 | Routine |
| cs1 | 001000 | 0×08 | 8 | 32 | 0×20 | 00100000 | 001 | 1 | 0 | 0 | 0 | Priority |
| af11 | 001010 | 0×0A | 10 | 40 | 0×28 | 00101000 | 001 | 1 | 0 | 1 | 0 | Priority |
| af12 | 001100 | 0×0C | 12 | 48 | 0×30 | 00110000 | 001 | 1 | 1 | 0 | 0 | Priority |
| af13 | 001110 | 0×0E | 14 | 56 | 0×38 | 00111000 | 001 | 1 | 1 | 1 | 0 | Priority |
| cs2 | 010000 | 0×10 | 16 | 64 | 0×40 | 01000000 | 010 | 2 | 0 | 0 | 0 | Immediate |
| af21 | 010010 | 0×12 | 18 | 72 | 0×48 | 01001000 | 010 | 2 | 0 | 1 | 0 | Immediate |
| af22 | 010100 | 0×14 | 20 | 80 | 0×50 | 01010000 | 010 | 2 | 1 | 0 | 0 | Immediate |
| af23 | 010110 | 0×16 | 22 | 88 | 0×58 | 01011000 | 010 | 2 | 1 | 1 | 0 | Immediate |
| cs3 | 011000 | 0×18 | 24 | 96 | 0×60 | 01100000 | 011 | 3 | 0 | 0 | 0 | Flash |
| af31 | 011010 | 0×1A | 26 | 104 | 0×68 | 01101000 | 011 | 3 | 0 | 1 | 0 | Flash |
| af32 | 011100 | 0×1C | 28 | 112 | 0×70 | 01110000 | 011 | 3 | 1 | 0 | 0 | Flash |
| af33 | 011110 | 0×1E | 30 | 120 | 0×78 | 01111000 | 011 | 3 | 1 | 1 | 0 | Flash |
| cs4 | 100000 | 0×20 | 32 | 128 | 0×80 | 10000000 | 100 | 4 | 0 | 0 | 0 | FlashOverride |
| af41 | 100010 | 0×22 | 34 | 136 | 0×88 | 10001000 | 100 | 4 | 0 | 1 | 0 | FlashOverride |
| af42 | 100100 | 0×34 | 36 | 144 | 0×90 | 10010000 | 100 | 4 | 1 | 0 | 0 | FlashOverride |
| af43 | 100110 | 0×26 | 38 | 152 | 0×98 | 10011000 | 100 | 4 | 1 | 1 | 0 | FlashOverride |
| cs5 | 101000 | 0×28 | 40 | 160 | 0xA0 | 10100000 | 101 | 5 | 0 | 0 | 0 | Critical |
| ef | 101110 | 0×2E | 46 | 184 | 0xB8 | 10111000 | 101 | 5 | 1 | 1 | 0 | Critical |
| cs6 | 110000 | 0×30 | 48 | 192 | 0xC0 | 11000000 | 110 | 6 | 0 | 0 | 0 | Internetworkcontrol |
| cs7 | 111000 | 0×38 | 56 | 224 | 0xE0 | 11100000 | 111 | 7 | 0 | 0 | 0 | Networkcontrol |