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changeip
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TOS

Sun Jan 21, 2007 2:25 am

If you mangle packets to change their TOS, or a SIP phone sets its TOS/DSCP value to a higher priority does Mikrotik do any prioritization automatically? Basically is setting TOS enough or does one need to also setup a queue ? I also see 802.1p priorities on SIP packets, but I'm not sure if a queue tree is required or this is done automatically by RouterOS. If there are no queues, isn't global-in and global-out still in effect and therefore prioritizing based on 802.1p ? Just curious really...

Sam

new-tos (max-reliability | max-throughput | min-cost | min-delay | normal integer) - specify TOS value to be used in conjunction with action=change-tos
max-reliability - maximize reliability (ToS=4)
max-throughput - maximize throughput (ToS=8)
min-cost - minimize monetary cost (ToS=2)
min-delay - minimize delay (ToS=16)
normal - normal service (ToS=0)
 
ldvaden
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Re: TOS

Sun Apr 15, 2007 2:09 pm

If you mangle packets to change their TOS, or a SIP phone sets its TOS/DSCP value to a higher priority does Mikrotik do any prioritization automatically? Basically is setting TOS enough or does one need to also setup a queue ? I also see 802.1p priorities on SIP packets, but I'm not sure if a queue tree is required or this is done automatically by RouterOS. If there are no queues, isn't global-in and global-out still in effect and therefore prioritizing based on 802.1p ? Just curious really...

Sam

new-tos (max-reliability | max-throughput | min-cost | min-delay | normal integer) - specify TOS value to be used in conjunction with action=change-tos
max-reliability - maximize reliability (ToS=4)
max-throughput - maximize throughput (ToS=8)
min-cost - minimize monetary cost (ToS=2)
min-delay - minimize delay (ToS=16)
normal - normal service (ToS=0)
This very good question has lied fallow for almost 90 days --- Is there someone who will answer the well posited question in the interest of the MikroTik community in any of the following categories:

.someone on the MikroTik staff

.a consultant on the list

.an experienced MikroTik licensee.

There are those of us who would be very appreciative.

Kind regards/ldv
 
bokad
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Sun Apr 15, 2007 5:19 pm

ROS does not do any automatic prioritization. You must mark packets and put them in a queue.
 
ldvaden
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Posts: 201
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Location: North Texas

Re: TOS

Mon Apr 23, 2007 10:55 pm

new-tos (max-reliability | max-throughput | min-cost | min-delay | normal integer) - specify TOS value to be used in conjunction with action=change-tos
max-reliability - maximize reliability (ToS=4)
max-throughput - maximize throughput (ToS=8)
min-cost - minimize monetary cost (ToS=2)
min-delay - minimize delay (ToS=16)
normal - normal service (ToS=0)
Below is a table taken from RFC 4594 and augmented with decimal values for DSCP; the decimal values were validated against <www.cisco.com/web/CA/ppt/design__day_presentation.ppt> BUT the MT TOS? values are a SWAG based on an assumption.

It would surely be nice if MikroTik were to augment the drop down box in 2.9.43 with the RFC names for the DSCP values (e.g., CS1, AF3, EF, yada 1, yada 2).

rgds/ldv
|--------------------------------------------------------------------------|
|   Service     |  DSCP   |    DSCP     DEC  MT |       Application        |
|  Class Name   |  Name   |    Value        TOS?|        Examples          |
|===============+=========+=====================+==========================|
|Network Control|  CS6    |   110000     48 192 | Network routing          |
|---------------+---------+---------------------+--------------------------|
| Telephony     |   EF    |   101110     46 184 | IP Telephony bearer      |
|---------------+---------+---------------------+--------------------------|
|  Signaling    |  CS5    |   101000            | IP Telephony signaling   |
|---------------+---------+---------------------+--------------------------|
| Multimedia    |AF41,AF42|100010,100100        |   H.323/V2 video         |
| Conferencing  |  AF43   |   100110     34 136 |  conferencing (adaptive) |
|---------------+---------+---------------------+--------------------------|
|  Real-Time    |  CS4    |   100000     32 128 | Video conferencing and   |
|  Interactive  |         |                     | Interactive gaming       |
|---------------+---------+---------------------+--------------------------|
| Multimedia    |AF31,AF32|011010,011100        | Streaming video and      |
| Streaming     |  AF33   |   011110     26 104 |   audio on demand        |
|---------------+---------+---------------------+--------------------------|
|Broadcast Video|  CS3    |   011000     24  96 |Broadcast TV & live events|
|---------------+---------+---------------------+--------------------------|
| Low-Latency   |AF21,AF22|010010,010100        |Client/server transactions|
|   Data        |  AF23   |   010110     18  72 | Web-based ordering       |
|---------------+---------+---------------------+--------------------------|
|     OAM       |  CS2    |   010000     16  64 |         OAM&P            |
|---------------+---------+---------------------+--------------------------|
|High-Throughput|AF11,AF12|001010,001100        |  Store and forward       |
|    Data       |  AF13   |   001110     10  40 |     applications         |
|---------------+---------+---------------------+--------------------------|
|    Standard   | DF (CS0)|   000000      0   0 | Undifferentiated         |
|               |         |                     | applications             |
|---------------+---------+---------------------+--------------------------|
| Low-Priority  |  CS1    |   001000      8  32 | Any flow that has no BW  |
|     Data      |         |                     | assurance                |
|--------------------------------------------------------------------------|

 
bokad
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Tue Apr 24, 2007 12:44 pm

DSCP only uses 6 bits in the TOS byte. The other two can still be used for ECN (explicit congestion notification). MT looks at all 8 bits in the byte.

So.... to convert between the DSCP decimal value and the MT TOS value, multiply by 4 :)

Now, to get DSCP value to decimal:
For the CSx values, multiple x by 8. ex. CS5 is decimal 40 is MT 160
For the AFxy values, use 8x + 2y. ex. AF32 is decimal 28 is MT 112
And DSCP EF is always decimal 46 is MT 184

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