10-09-2005 01:45 AM - edited 03-15-2019 03:44 AM
Hi,
There is a CallManager servcie called Tos Bitmask For Comm Between CCM and Device.
It says it is used for communication between CM and devices i.e signaling/stimulas
The default value is 0x68 in binary thats 1101000 or 104 in decimal.
How is the ToS/DSCP setting in the IP header calculated from the default value 0x68 ? I thought the default for DSCP was 26
Thanks
10-09-2005 09:24 AM
ToS of 0x68 (104 decimal) is equal to DSCP 26.
The formula is DSCP * 4, so 26*4=104,
ToS Byte of IP Header is 8 bits, 6 of which are the DSCP bits and the last two are Flow control bits, so
011010 00 -> ToS 104, DSCP (first 6 bits) = 26.
The first 3 bits represent also IP precedance, so in this case 011 - IP precedance = 3
Consider DSCP 46 (RTP) as another example
ToS = 46*4=184
10111000, ip precedence = 5
Hope this helps,
Chris
10-09-2005 11:17 PM
Thanks Chris !
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