Re: [j-nsp] RED Drops with Qos
Scott,
I think the packet dropping is unavoidable, no matter how you configure RED.
Most of the time, your TCP is in congestion avoidance state, it increases
its transmission window size by one every RTT (round trip time). In other
words, it will increase its transmission rate till congestion happens (that
is when RED or tail drop kicks in). After TCP detects packet drops, it will
decrease its window size by half ,and start increasing its transmission
window size by one every RTT till congestion happens again.
If you are using MS Windows TCP, Windows has a default limit on the maximum
TCP window size (I do not remember the exact number). So if you have enough
number of T1 to support the maximum TCP transmission rate limited by the
maximum window size, you will not see drops. You can also change the
maximum TCP window size to much larger number by editing the registry.
Li
On Mon, Dec 21, 2009 at 4:58 PM, Scott Berkman sc...@sberkman.net wrote:
Derick,
FYI after making your suggested changes I am still seeing drops:
show configuration chassis fpc 2 pic 2
red-buffer-occupancy {
weighted-averaged {
instant-usage-weight-exponent 9;
}
}
show interfaces queue ds-2/2/0:1:5:1
Physical interface: ds-2/2/0:1:5:1, Enabled, Physical link is Up
Interface index: 165, SNMP ifIndex: 79
Description: Test-1
Forwarding classes: 4 supported, 4 in use
Egress queues: 4 supported, 4 in use
Queue: 0, Forwarding classes: be
Queued:
Packets : 290 0 pps
Bytes:375596 0 bps
Transmitted:
Packets : 268 0 pps
Bytes:346908 0 bps
Tail-dropped packets : 0 0 pps
RED-dropped packets :22 0 pps
Low, non-TCP: 0 0 pps
Low, TCP:22 0 pps
High, non-TCP : 0 0 pps
High, TCP : 0 0 pps
RED-dropped bytes: 28688 0 bps
Low, non-TCP: 0 0 bps
Low, TCP: 28688 0 bps
High, non-TCP : 0 0 bps
High, TCP : 0 0 bps
Thanks,
-Scott
-Original Message-
From: juniper-nsp-boun...@puck.nether.net
[mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of Derick Winkworth
Sent: Monday, December 21, 2009 4:41 PM
To: juniper-nsp@puck.nether.net
Subject: Re: [j-nsp] RED Drops with Qos
By default, in JUNOS, there is no weighted average for RED. Queue-depth is
evaluated in an instantaneous fashion. This means, of course, that there
is
no allowing for transient bursts.
Under the chassis/pic hierarchy you must enable weighted-average RED and
you
should put a weight of 9 as a start.
From: Scott Berkman sc...@sberkman.net
To: juniper-nsp@puck.nether.net
Sent: Mon, December 21, 2009 3:11:40 PM
Subject: [j-nsp] RED Drops with Qos
Hi All,
I'm fairly new to Juniper, and I am trying to get our QoS
setup right on a M20 running JunOS 8.3 being used for T1 aggregation.
The PIC is an IQ-enabled ChOC12 card, and the interfaces are
channelized T1's. We seem to be classifying traffic into the 4 queues
correctly, but no matter what I change in the settings I am still seeing
RED
drops on TCP/Low traffic.
Please find below the base configuration sections I am starting with. I
have tried some different percentages, and tried defining specific
drop-policies based on some suggestions in the achieves from this list, but
no matter what I still see the drops in the same place.
Are there any good best-practice guides to QoS on JunOS? I
see lots about how the different settings effect the flow, but nothing in
terms of what works well for others. Also is there anything obviously
wrong
below?
Thanks in advance for any help,
-Scott
classifiers {
dscp DSCP-CLASS {
forwarding-class ef {
loss-priority low code-points 101110;
}
forwarding-class af {
loss-priority low code-points [ 011000 011010 ];
}
forwarding-class be {
loss-priority low code-points 00;
}
forwarding-class nc {
loss-priority low code-points 111000;
}
}
forwarding-classes {
queue 0 be;
queue 1 ef;
queue 2 af;
queue 3 nc;
}
scheduler-maps {
VOIP-MAP
Re: [j-nsp] RED Drops with Qos
By default, in JUNOS, there is no weighted average for RED. Queue-depth is
evaluated in an instantaneous fashion. This means, of course, that there is no
allowing for transient bursts.
Under the chassis/pic hierarchy you must enable weighted-average RED and you
should put a weight of 9 as a start.
From: Scott Berkman sc...@sberkman.net
To: juniper-nsp@puck.nether.net
Sent: Mon, December 21, 2009 3:11:40 PM
Subject: [j-nsp] RED Drops with Qos
Hi All,
I'm fairly new to Juniper, and I am trying to get our QoS
setup right on a M20 running JunOS 8.3 being used for T1 aggregation.
The PIC is an IQ-enabled ChOC12 card, and the interfaces are
channelized T1's. We seem to be classifying traffic into the 4 queues
correctly, but no matter what I change in the settings I am still seeing RED
drops on TCP/Low traffic.
Please find below the base configuration sections I am starting with. I
have tried some different percentages, and tried defining specific
drop-policies based on some suggestions in the achieves from this list, but
no matter what I still see the drops in the same place.
Are there any good best-practice guides to QoS on JunOS? I
see lots about how the different settings effect the flow, but nothing in
terms of what works well for others. Also is there anything obviously wrong
below?
Thanks in advance for any help,
-Scott
classifiers {
dscp DSCP-CLASS {
forwarding-class ef {
loss-priority low code-points 101110;
}
forwarding-class af {
loss-priority low code-points [ 011000 011010 ];
}
forwarding-class be {
loss-priority low code-points 00;
}
forwarding-class nc {
loss-priority low code-points 111000;
}
}
forwarding-classes {
queue 0 be;
queue 1 ef;
queue 2 af;
queue 3 nc;
}
scheduler-maps {
VOIP-MAP {
forwarding-class be scheduler be-sched;
forwarding-class ef scheduler ef-sched;
forwarding-class af scheduler af-sched;
forwarding-class nc scheduler nc-sched;
}
}
schedulers {
be-sched {
transmit-rate percent 10;
buffer-size percent 10;
priority low;
}
ef-sched {
transmit-rate percent 80;
buffer-size percent 80;
priority strict-high;
}
af-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
nc-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
}
Example interface:
ds-2/2/0:1:1:1 {
scheduler-map VOIP-MAP;
unit 0 {
classifiers {
dscp DSCP-CLASS;
}
}
}
I also tested with the following scheduler and still saw the drops:
be-sched {
transmit-rate percent 80;
buffer-size percent 80;
priority high;
}
ef-sched {
transmit-rate percent 10;
buffer-size percent 10;
priority high;
}
af-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
nc-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
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Re: [j-nsp] RED Drops with Qos
Thanks Derick,
I read about changing the RED method, but missed that it is done on
the chassis/pic level, not in the drop-policies.
I'll try this out and see where it gets us.
On a related note, I saw some back and forth about setting the
percentages (transmit-rate and buffer-size) on strict-high queues to other
than 0. What are everyone's best recommendations/past successes on this?
Thanks again!
-Scott
-Original Message-
From: juniper-nsp-boun...@puck.nether.net
[mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of Derick Winkworth
Sent: Monday, December 21, 2009 4:41 PM
To: juniper-nsp@puck.nether.net
Subject: Re: [j-nsp] RED Drops with Qos
By default, in JUNOS, there is no weighted average for RED. Queue-depth is
evaluated in an instantaneous fashion. This means, of course, that there is
no allowing for transient bursts.
Under the chassis/pic hierarchy you must enable weighted-average RED and you
should put a weight of 9 as a start.
From: Scott Berkman sc...@sberkman.net
To: juniper-nsp@puck.nether.net
Sent: Mon, December 21, 2009 3:11:40 PM
Subject: [j-nsp] RED Drops with Qos
Hi All,
I'm fairly new to Juniper, and I am trying to get our QoS
setup right on a M20 running JunOS 8.3 being used for T1 aggregation.
The PIC is an IQ-enabled ChOC12 card, and the interfaces are
channelized T1's. We seem to be classifying traffic into the 4 queues
correctly, but no matter what I change in the settings I am still seeing RED
drops on TCP/Low traffic.
Please find below the base configuration sections I am starting with. I
have tried some different percentages, and tried defining specific
drop-policies based on some suggestions in the achieves from this list, but
no matter what I still see the drops in the same place.
Are there any good best-practice guides to QoS on JunOS? I
see lots about how the different settings effect the flow, but nothing in
terms of what works well for others. Also is there anything obviously wrong
below?
Thanks in advance for any help,
-Scott
classifiers {
dscp DSCP-CLASS {
forwarding-class ef {
loss-priority low code-points 101110;
}
forwarding-class af {
loss-priority low code-points [ 011000 011010 ];
}
forwarding-class be {
loss-priority low code-points 00;
}
forwarding-class nc {
loss-priority low code-points 111000;
}
}
forwarding-classes {
queue 0 be;
queue 1 ef;
queue 2 af;
queue 3 nc;
}
scheduler-maps {
VOIP-MAP {
forwarding-class be scheduler be-sched;
forwarding-class ef scheduler ef-sched;
forwarding-class af scheduler af-sched;
forwarding-class nc scheduler nc-sched;
}
}
schedulers {
be-sched {
transmit-rate percent 10;
buffer-size percent 10;
priority low;
}
ef-sched {
transmit-rate percent 80;
buffer-size percent 80;
priority strict-high;
}
af-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
nc-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
}
Example interface:
ds-2/2/0:1:1:1 {
scheduler-map VOIP-MAP;
unit 0 {
classifiers {
dscp DSCP-CLASS;
}
}
}
I also tested with the following scheduler and still saw the drops:
be-sched {
transmit-rate percent 80;
buffer-size percent 80;
priority high;
}
ef-sched {
transmit-rate percent 10;
buffer-size percent 10;
priority high;
}
af-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
nc-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
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Re: [j-nsp] RED Drops with Qos
Derick,
FYI after making your suggested changes I am still seeing drops:
show configuration chassis fpc 2 pic 2
red-buffer-occupancy {
weighted-averaged {
instant-usage-weight-exponent 9;
}
}
show interfaces queue ds-2/2/0:1:5:1
Physical interface: ds-2/2/0:1:5:1, Enabled, Physical link is Up
Interface index: 165, SNMP ifIndex: 79
Description: Test-1
Forwarding classes: 4 supported, 4 in use
Egress queues: 4 supported, 4 in use
Queue: 0, Forwarding classes: be
Queued:
Packets : 290 0 pps
Bytes:375596 0 bps
Transmitted:
Packets : 268 0 pps
Bytes:346908 0 bps
Tail-dropped packets : 0 0 pps
RED-dropped packets :22 0 pps
Low, non-TCP: 0 0 pps
Low, TCP:22 0 pps
High, non-TCP : 0 0 pps
High, TCP : 0 0 pps
RED-dropped bytes: 28688 0 bps
Low, non-TCP: 0 0 bps
Low, TCP: 28688 0 bps
High, non-TCP : 0 0 bps
High, TCP : 0 0 bps
Thanks,
-Scott
-Original Message-
From: juniper-nsp-boun...@puck.nether.net
[mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of Derick Winkworth
Sent: Monday, December 21, 2009 4:41 PM
To: juniper-nsp@puck.nether.net
Subject: Re: [j-nsp] RED Drops with Qos
By default, in JUNOS, there is no weighted average for RED. Queue-depth is
evaluated in an instantaneous fashion. This means, of course, that there is
no allowing for transient bursts.
Under the chassis/pic hierarchy you must enable weighted-average RED and you
should put a weight of 9 as a start.
From: Scott Berkman sc...@sberkman.net
To: juniper-nsp@puck.nether.net
Sent: Mon, December 21, 2009 3:11:40 PM
Subject: [j-nsp] RED Drops with Qos
Hi All,
I'm fairly new to Juniper, and I am trying to get our QoS
setup right on a M20 running JunOS 8.3 being used for T1 aggregation.
The PIC is an IQ-enabled ChOC12 card, and the interfaces are
channelized T1's. We seem to be classifying traffic into the 4 queues
correctly, but no matter what I change in the settings I am still seeing RED
drops on TCP/Low traffic.
Please find below the base configuration sections I am starting with. I
have tried some different percentages, and tried defining specific
drop-policies based on some suggestions in the achieves from this list, but
no matter what I still see the drops in the same place.
Are there any good best-practice guides to QoS on JunOS? I
see lots about how the different settings effect the flow, but nothing in
terms of what works well for others. Also is there anything obviously wrong
below?
Thanks in advance for any help,
-Scott
classifiers {
dscp DSCP-CLASS {
forwarding-class ef {
loss-priority low code-points 101110;
}
forwarding-class af {
loss-priority low code-points [ 011000 011010 ];
}
forwarding-class be {
loss-priority low code-points 00;
}
forwarding-class nc {
loss-priority low code-points 111000;
}
}
forwarding-classes {
queue 0 be;
queue 1 ef;
queue 2 af;
queue 3 nc;
}
scheduler-maps {
VOIP-MAP {
forwarding-class be scheduler be-sched;
forwarding-class ef scheduler ef-sched;
forwarding-class af scheduler af-sched;
forwarding-class nc scheduler nc-sched;
}
}
schedulers {
be-sched {
transmit-rate percent 10;
buffer-size percent 10;
priority low;
}
ef-sched {
transmit-rate percent 80;
buffer-size percent 80;
priority strict-high;
}
af-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
nc-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
}
Example interface:
ds-2/2/0:1:1:1 {
scheduler-map VOIP-MAP;
unit 0 {
classifiers {
dscp DSCP-CLASS;
}
}
}
I also tested with the following scheduler and still saw the drops:
be-sched {
transmit-rate percent 80;
buffer-size
Re: [j-nsp] RED Drops with Qos
Enable extended buffer size..
q-pic-large-buffer
also under chassis/pic configuration.
From: Scott Berkman sc...@sberkman.net
To: Derick Winkworth dwinkwo...@att.net; juniper-nsp@puck.nether.net
Sent: Mon, December 21, 2009 3:58:45 PM
Subject: RE: [j-nsp] RED Drops with Qos
Derick,
FYI after making your suggested changes I am still seeing drops:
show configuration chassis fpc 2 pic 2
red-buffer-occupancy {
weighted-averaged {
instant-usage-weight-exponent 9;
}
}
show interfaces queue ds-2/2/0:1:5:1
Physical interface: ds-2/2/0:1:5:1, Enabled, Physical link is Up
Interface index: 165, SNMP ifIndex: 79
Description: Test-1
Forwarding classes: 4 supported, 4 in use
Egress queues: 4 supported, 4 in use
Queue: 0, Forwarding classes: be
Queued:
Packets : 290 0 pps
Bytes:375596 0 bps
Transmitted:
Packets : 268 0 pps
Bytes:346908 0 bps
Tail-dropped packets : 0 0 pps
RED-dropped packets :22 0 pps
Low, non-TCP: 0 0 pps
Low, TCP:22 0 pps
High, non-TCP : 0 0 pps
High, TCP : 0 0 pps
RED-dropped bytes: 28688 0 bps
Low, non-TCP: 0 0 bps
Low, TCP: 28688 0 bps
High, non-TCP : 0 0 bps
High, TCP : 0 0 bps
Thanks,
-Scott
-Original Message-
From: juniper-nsp-boun...@puck.nether.net
[mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of Derick Winkworth
Sent: Monday, December 21, 2009 4:41 PM
To: juniper-nsp@puck.nether.net
Subject: Re: [j-nsp] RED Drops with Qos
By default, in JUNOS, there is no weighted average for RED. Queue-depth is
evaluated in an instantaneous fashion. This means, of course, that there is
no allowing for transient bursts.
Under the chassis/pic hierarchy you must enable weighted-average RED and you
should put a weight of 9 as a start.
From: Scott Berkman sc...@sberkman.net
To: juniper-nsp@puck.nether.net
Sent: Mon, December 21, 2009 3:11:40 PM
Subject: [j-nsp] RED Drops with Qos
Hi All,
I'm fairly new to Juniper, and I am trying to get our QoS
setup right on a M20 running JunOS 8.3 being used for T1 aggregation.
The PIC is an IQ-enabled ChOC12 card, and the interfaces are
channelized T1's. We seem to be classifying traffic into the 4 queues
correctly, but no matter what I change in the settings I am still seeing RED
drops on TCP/Low traffic.
Please find below the base configuration sections I am starting with. I
have tried some different percentages, and tried defining specific
drop-policies based on some suggestions in the achieves from this list, but
no matter what I still see the drops in the same place.
Are there any good best-practice guides to QoS on JunOS? I
see lots about how the different settings effect the flow, but nothing in
terms of what works well for others. Also is there anything obviously wrong
below?
Thanks in advance for any help,
-Scott
classifiers {
dscp DSCP-CLASS {
forwarding-class ef {
loss-priority low code-points 101110;
}
forwarding-class af {
loss-priority low code-points [ 011000 011010 ];
}
forwarding-class be {
loss-priority low code-points 00;
}
forwarding-class nc {
loss-priority low code-points 111000;
}
}
forwarding-classes {
queue 0 be;
queue 1 ef;
queue 2 af;
queue 3 nc;
}
scheduler-maps {
VOIP-MAP {
forwarding-class be scheduler be-sched;
forwarding-class ef scheduler ef-sched;
forwarding-class af scheduler af-sched;
forwarding-class nc scheduler nc-sched;
}
}
schedulers {
be-sched {
transmit-rate percent 10;
buffer-size percent 10;
priority low;
}
ef-sched {
transmit-rate percent 80;
buffer-size percent 80;
priority strict-high;
}
af-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
nc-sched {
transmit-rate percent 5;
buffer-size percent 5;
priority high;
}
}
Example
