04-04-2009 02:45 PM - edited 03-06-2019 04:59 AM
I just installed a new 3825 for our internet router. Very happy with it.
However now I need to reserver a certain amount of bandwidth for outbound video conference connections. We currently have a 70Mbps connection. Our average utilization is 30 percent on a busy day.
However it is possible for 1 or 2 people to saturate the link pending downloads.
How do I reserve 5 Mbps of bandwidth just for the video conference connections ? I would hate the VP's to try a vid call out and not have it work optimally b/c someone was downloading the newest version of linux and saturating the link.
Any help would be appreciated.
Cheers
Dave
Solved! Go to Solution.
04-05-2009 06:49 PM
policy-map testpol1
class test_class1
bandwidth 5000
shape average 5000000
policy-map main_pol1
class class-default
shape average 20000000
service-policy testpol1
NB: The above might not be accepted, if not, you could try:
policy-map main_pol1
class test_class1
bandwidth 5000
shape average 5000000
class class-default
shape average 15000000
04-04-2009 06:25 PM
Hi Dave
you can do it ofcourse
but there is things you need to consider wen you do QOS
now how the router will know this traffic is your video or it is not ?
the answer is there is many ways to know it this is called clasifications
if you have cisco switches and your video has some sort of L2 or L3 marking you can mark and trust that QOS marking from the switches and then reserve that amount of bandwidth in the router in terface
i wil lassum you dont have experience with this stage and you only concerned about the bandwidth reservation on the router outbound interface
in this case we need to clisify the traffic in the router it self
lets say you video use IP address 10.1.1.1
ok ( if it use range use that range same idea)
lets match that traffic from that endpoint first
access-list 100 permit ip host 10.1.1.1 any
class-map video-calss
match access-group 100
policy-map video-policy
class video-calss
bamdwidth 50000
now here i will do it for in way called nest QOS we will shape the overall interface bandwith to 70M and we will use the above policy under it
now this is to shape oveall interface bandwidth this will help you to have som sort of buffer
policy-map main-policy
class class-default
shape avrrage 70000000
service-policy video-policy
now lets apply it to the interface
dont forget to make the interface bandwidth as 70 Mb this way the policy will com to the effect when the 70 M is conjested
interface Fa0/0
bandwith 70000
service-policy output main-policy
this should be to output interface to WAN or internet or whatever outside connection u use
above is one way i think simple way for you there is alot of ways to achieve the same
good luck
if helpful Rate
04-05-2009 07:49 AM
Great reply and explanation, thanks alot. I know all of my outbound video traffic will be coming from one public IP so I should be able to match that fine. I noticed your policy-map restricted the bandwidth to 50000, but if I read right it should be 5000 for 5Mbps correct ?
I'll test this in the lab tonight.
Cheers
Dave
04-05-2009 08:29 AM
Some additional notes to what Marwan suggested.
When shaping for Ethernet, you might want to account for Ethernet framing overhead. I.e. shape 10% to 15% slower than "nomimal" bandwidth.
On many platforms (pre 12.4.20T), class-default defaults to WFQ which competes against defined class flows. To avoid this, configure the class-default to FIFO.
PS:
If your average utilization is a low as you note, you might not need to define a sub-policy because GTS shaping, itself, uses WFQ (again on many platforms, pre 12.4.20T).
PPS:
"someone was downloading the newest version of linux and saturating the link. "
Downloading would be saturation inbound? If so, different (harder) problem.
04-05-2009 05:45 PM
So I am trying this in the lab right now on a test 2651XM router. Here is the config. Essentially I have 4 laptops, 2 on each side of the router. I have set the shape average to 20Mbps for the link as well as the bandwidth for the interface. The 2 laptops in 192.168.10.0 subnet are both copying a 700MB file to each of the laptops across the router.
So laptop (10.3) starts the copy and max's out the 20Mbps. Then laptop (10.2) starts its copy and I should see its bandwidth limited to 5Mpbs, but it actually ramps up to 12Mbps. So it doesnt see to be limiting it 5Mbps. Any thoughts ?
Building configuration...
Current configuration : 1129 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname test1
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$tfdP$A4sL2IBIRs62BRaJgwvGv0
!
no aaa new-model
no network-clock-participate slot 1
no network-clock-participate wic 0
ip cef
multilink bundle-name authenticated
archive
log config
hidekeys
!
!
!
class-map match-all test_class1
match access-group 101
!
!
policy-map testpol1
class test_class1
bandwidth 5000
policy-map main_pol1
class class-default
shape average 20000000
service-policy testpol1
!
interface FastEthernet0/0
ip address 192.168.10.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
bandwidth 20000
ip address 192.168.20.1 255.255.255.0
duplex auto
speed auto
service-policy output main_pol1
!
ip forward-protocol nd
!
ip http server
!
access-list 101 permit ip host 192.168.10.2 host 192.168.20.3
snmp-server community test RW
!
control-plane
!
!
line con 0
line aux 0
line vty 0 4
password test
login
!
!
end
04-05-2009 05:51 PM
Test_class1 isn't limited to 5 Mbps. Bandwidth statement within a class policy defines a minimum, not a maximum.
04-05-2009 05:55 PM
Is there way to define this as a maximum ?
04-05-2009 06:49 PM
policy-map testpol1
class test_class1
bandwidth 5000
shape average 5000000
policy-map main_pol1
class class-default
shape average 20000000
service-policy testpol1
NB: The above might not be accepted, if not, you could try:
policy-map main_pol1
class test_class1
bandwidth 5000
shape average 5000000
class class-default
shape average 15000000
04-05-2009 07:37 PM
Well the first config was accepted but didnt work, but the 2nd one did !!
Now my first connection consumes 15Mbps and the 2nd one which is defined by the ACL consumes 5Mbps that was reserved.
Excellent...thanks for your help.
Cheers
Dave
04-06-2009 04:08 AM
Great!
I wasn't sure about the first config (i.e. nested shapers) would be acceptable to the router. (It might work with 12.4.20T or later QoS.)
Do keep in mind, the disadvantage of the 2nd approach, it also limits all other traffic to 15 Mbps, even if the other 5 Mbps is available. (Sometimes we're forced into a less than optimal QoS model yet one that provides the service guarantees we require.)
04-06-2009 04:14 AM
Yeah I realised that, but it should work fine.
Thanks again.
Dave
04-06-2009 04:22 AM
i think both of them works fine
but why with the next one u have given the other traffic 15Mb what about the other 5M
is it becuase of the MAX bandwidth that can be allocated is 75% of the interface ?
and this come to effect after we put the bandwith command under the interface ?
thank you
04-06-2009 02:24 PM
sorry guys
i asked because i thought you talking about the ogiginal question while you talking about the lab example
i think in this case the example 2 wil work
as you need in total only 20M
04-07-2009 12:36 AM
hi Joseph
i am wonderring here we given the interface bandwidth as 20M
and th epolicy used in the shper GTS 20M
why we didnt got error becuase by default the interface should le us to use 75% of the interface bandwidth
and we can chamge it by the commad max-reserved
any idea ?
04-07-2009 03:08 AM
Marwan, I suspect the problem with the one suggested hiearchal policy was due to nested shapers, not anything with max-reserve. In that example, the child policy defined 5 Mbps (25%) of parent's 20 Mbps bandwidth. If it had tried to define more than 15 Mbps (75%) than the default for max-reserve could be an issue. Further, believe the max-reserve would only apply to the bandwidth statement, not the shaper.
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