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QOS giving outbound priority to a port, is it possible with C850/IOS 12.3?

bbiales00
Level 1
Level 1

I've got a realtime application that uses a particular port, say, 9000 for inbound and outbound UDP traffic. Since I have off-site users that can use up all my outbound bandwidth at times, when they do this, the realtime app suffers. I would love to give this port priority, so these packets go out first no matter what else is going on (I know I cannot control the order the packets arrive...). Unfortunately, I have little IOS experience. I can tweak Access lists and NAT settings, but I don't see how to do this QOS feature with my router. Is it even possible? I've been told it will support QOS, but I'm not so sure... If my current config would help, let me know and I will post it.

Thanks for any insights/direction you can provide.

1 Accepted Solution

Accepted Solutions

What is the output from:- set ip ?

If DSCP is not vailable - then IP Precendence 5 is the same and as good as.

Once you have applied the policy - and the traffic is being marked, then you can prioritise the traffic for the app!

View solution in original post

22 Replies 22

andrew.prince
Level 10
Level 10

Brian,

Have you got a 850 or a 805?

It appears to be an 857, here is the result of show version with the stuff about cryptographic export cut out...

#sh ver

Cisco IOS Software, C850 Software (C850-ADVSECURITYK9-M), Version 12.3(8)YI1, RE LEASE SOFTWARE (fc1)

Synched to technology version 12.3(10.3)T2

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2005 by Cisco Systems, Inc.

Compiled Fri 22-Apr-05 16:04 by ealyon

ROM: System Bootstrap, Version 12.3(8r)YI1, RELEASE SOFTWARE

ROM: Cisco IOS Software, C850 Software (C850-ADVSECURITYK9-M), Version 12.3(8)YI 1, RELEASE SOFTWARE (fc1)

r12 uptime is 28 weeks, 1 day, 1 hour, 24 minutes

System returned to ROM by power-on

System image file is "flash:c850-advsecurityk9-mz.123-8.YI1.bin"

Cisco 857 (MPC8272) processor (revision 0x100) with 59392K/6144K bytes of memory .

Processor board ID FHK092922S0

MPC8272 CPU Rev: Part Number 0xC, Mask Number 0x10

4 FastEthernet interfaces

1 ATM interface

128K bytes of non-volatile configuration memory.

20480K bytes of processor board System flash (Intel Strataflash)

Configuration register is 0x2102

I cannot tell from your posting if you can apply a QoS policy on your device.

Try to see if it's possible, in your configuration try creating a test policy:

access-list 101 permit udp any any eq 9000

class-map match-all pri-app

match access-group 101

policy-map mark-app

class pri-app

set dscp ef

interface ethernet or fa x/x

service-policy input mark-app

Once all the above is in, to see if it's working at the cli type:-

show policy-map interface e or fa x/x

You want to see something like:-

Class-map: pri-app (match-all)

5982400 packets, 368368823 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: access-group 101

QoS Set

dscp EF

Packets marked 5982400

Well, it doesn't look so good... I went to configuration in terminal mode, and it didn't like the second line (class-map). So I guess I need a new router if I want QOS? Or did I have to turn on QOS before entering these commands?

Here is the output:

r12(config)#access-list 101 permit udp any any eq 1194

r12(config)#class-map mark-voip

^

% Invalid input detected at '^' marker.

just pulled this from a data sheet @:-

http://www.cisco.com/en/US/prod/collateral/routers/ps380/ps6200/prod_qas0900aecd8028a982.html

Q. What QoS features are supported on the Cisco 870 platforms?

A. The Cisco 870 Series supports advanced QoS features on the WAN interface to strictly prioritize different types of traffic, especially voice traffic. These advanced QoS features include Class-Based Weighted Fair Queuing (CBWFQ), Low Latency Queuing (LLQ), class-based marking, policing, Class-Based Weighted Random Early Detection (CBWRED), Network-Based Address Recognition (NBAR), QoS preclassify, prefragmentation, Resource Reservation Protocol (RSVP), Priority and Custom queuing, and LFI. Starting with Cisco IOS Software Releases 12.4(9)T2 and 12.4(11)T, DSCP and IP precedence marking are also supported on the LAN using the switched virtual interface (SVI).

Q. What QoS features are supported on the Cisco 850 platforms?

A. The Cisco 850 Series supports basic QoS features, such as weighted fair queuing (WFQ), policy-based routing (PBR), per-VC queuing, per-VC traffic shaping. NOTE: Cisco 850 does not support the advanced QoS features listed for voice.

In essence - you need another router :o(

Ok, then, I've got another router :-)

I've replaced the 857 with an 877, and your suggested commands are not quite working, but close. You have to bear with me, I know how to change NAT's and do some access-list stuff, but applying policy to interfaces is new to me. So here's what I've got...

I was able to enter a slightly modified version of what you suggested, here's how far I've gotten, I had to change your line:

set dscp ef

to

set precedence critical

So now in my config I have this class setup:

class-map match-all pri-app

match access-group 101

!

!

policy-map mark-app

class pri-app

set precedence 5

!

!

And of course I have the access-list 101 setup as:

access-list 101 permit udp any any eq 9000

Now I assume I have to turn this policy on at one or more interfaces, you said to enter:

interface ethernet or fa x/x

service policy mark-app

Give the following info, do I turn this on for interface Dialer1, or VLAN1? or all 4 FastEthernet interfaces? All of the above?

The interfaces I have are (from my config file):

interface ATM0

no ip address

no atm ilmi-keepalive

dsl operating-mode auto

!

interface ATM0.1 point-to-point

pvc 0/35

pppoe-client dial-pool-number 1

!

!

interface FastEthernet0

no cdp enable

!

interface FastEthernet1

no cdp enable

!

interface FastEthernet2

no cdp enable

!

interface FastEthernet3

no cdp enable

!

interface Vlan1

description $ETH-SW-LAUNCH$$INTF-INFO-HWIC 4ESW$

ip address 192.168.55.1 255.255.255.0

ip nat inside

ip virtual-reassembly

ip tcp adjust-mss 1400

!

interface Dialer1

ip address negotiated

ip nat outside

ip virtual-reassembly

encapsulation ppp

dialer pool 1

no cdp enable

ppp authentication pap callin

ppp pap sent-username myUserName password 0 myPasswrd

!

So do I enter:

interface Vlan 1

service policy mark-app

or

interface fa 0

service policy mark-app

interface fa 1

service policy mark-app

interface fa 2

service policy mark-app

interface fa 3

service policy mark-app

Please help me solve this last part of the puzzle :-)

Thanks a lot!

Brian,

You would place the policy map on the interface where you expect the application traffic to originate at layer 3? So the VLAN interface would be where I would place it, and place it in-bound - coming in from the LAN would be your best bet.

Are you sure you cannot set the marking as DSCP?? I have not configured a 8xx router so I do not know - can you post the output from a set ? in the class map?

Here it is:

r12(config-pmap-c)#set ?

atm-clp Set ATM CLP bit to 1

cos Set IEEE 802.1Q/ISL class of service/user priority

discard-class Discard behavior identifier

fr-de Set FR DE bit to 1

ip Set IP specific values

mpls Set MPLS specific values

precedence Set precedence in IP(v4) and IPv6 packets

qos-group Set QoS Group

What is the output from:- set ip ?

If DSCP is not vailable - then IP Precendence 5 is the same and as good as.

Once you have applied the policy - and the traffic is being marked, then you can prioritise the traffic for the app!

Ok,

I tried set ip ?

and just get "set ip precedence"

But "set ip precedence ?" returns an error at the ?

I did the "show policy-map interface vlan1" and it showed zero packets.

So I changed my access-list to also include

"permit udp any eq 1194 any"

as well as " permit udp any any eq 1194",

and then the "show policy-map" showed some figures:

r12#show policy-map interface vlan1

Vlan1

Service-policy input: mark-app

Class-map: pri-app (match-all)

793 packets, 160831 bytes

5 minute offered rate 3000 bps, drop rate 0 bps

Match: access-group 101

QoS Set

precedence 5

Packets marked 793

Class-map: class-default (match-any)

66126 packets, 8997475 bytes

5 minute offered rate 5000 bps, drop rate 0 bps

Match: any

so it seems to be working!

Thanks again!

Oh... One more question though...

You said:

"Once you have applied the policy - and the traffic is being marked, then you can prioritise the traffic for the app!"

Does that mean I still have one more step? Or that this is now prioritizing the packets?

Thanks!

Yep - you are marking the relevant traffic, now you need to prioritise it. So now you need to write another policy placing the markedt traffic into your priority queue.

Just to also be clear - do you have any other traffic you wat to also prioritise? or is this app just it?

Well, once I've gotten the hang of this, there could well be other things to prioritize. For instance, I have a web page used for customers to download rather large files via HTTP / HTTPS. I'd actually like to drop the priority of these packets, so any outbound traffic required by other applications will always take precedence. This is easy traffic to recognize, as I know the source address and port for that app.

So how do I now put these marked packets in the high priority queue, then? I guess I figured that would happen automatically, since I marked them as "critical"...

Thanks again.

You now need to created a policy-map to prioritise the marked packets outbound on your link. Is your internet connecction in the same router over ADSL? What is the speed of your internet circuit?

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