UWN QOS questions
Hello all.
I've got two questions related to wireless QOS in a UWN world:
1) A QOS profile is associated with a WLAN. Is it possible to diferentiate traffic within a single WLAN? Can I assign the gold profile to one DSCP value, and the silver profile to another DSCP - all within the same WLAN? If not, how do others differentiate between applications on a mobile device (email vs. softphone)?
2) Is it possible for the LWAPP AP to remap or set incoming DSCP - the classification and marking functions of QOS (aka establish the QOS classification boundry on the radio). If not, I'm concerned about the WLC maintaining potentially invalid DSCP in the LWAPP header on the way to the controller. How do others ensure they aren't oversubscribing a priority queue on a WAN link from an H-REAP AP to a central site controller?
Unfortunately, I'm almost positive the answer to both questions is NO.
From the document you referenced -
"The controller does not apply its own QoS. The QoS support on the WLC gives the WLC the ability to apply the same priority that is set on the wire (or application). Therefore, the only action a WLC or AP will do is copy the value of the original packet to the outer header of the LWAPP packet."
For question 1, to use different QOS profiles, we must associate clients to different WLANs. The result is that we are limited to device-specific QOS, as opposed to application-specific QOS. If we want VoIP or Video over wireless, the endpoints (e.g. VoIP handsets) must connect to their own SSID. Softphone traffic can't be preferred over other PC traffic.
For question 2, this means we need to be concerned about the LWAPP AP maintaining potentially invalid DSCP in the LWAPP header on the way to the controller (and vice-versa). The problem comes in that this may oversubscribe a priority queue on a WAN link from a remote AP to a central site controller, unless you are policing at L3 ingress (which isn't without problems too). The way around this is to conditionally clear DSCP on ingress (e.g. not trusting the controller or AP uplink).
Similar Messages
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Hello,
Out company is finally going to install VOIP, they will be using something called Natterbox, but I've been asked to add QoS to our Cisco switches and routers in various locations I will also need to add a second VLAN for voice I believe which is ok.
How can we configure QoS so VOIP is treated first then video streaming then video?
As we will need to add a second VLAN, so I assum all ports to phone swill be truk ports?
ThanksAndy,
To start, you need to understand how the soft phone and desk phones mark voice traffic. Cisco switch and Routers perform QoS by trusting, understanding or marking traffic using DSCP, PHB and port numbers.
Hence questions you need to ask are
1. Do the softphones mark their voice and video traffic? If they do how do they do it?
2. What ports are used for voice traffic?
3. what ports are used for signalling traffic
4.What ports are used for video traffic if its differs from ports used for voice.
Once these facts are understood, you can beging to look at how to configure your switches and routers based on this parameters
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"opportunity is a haughty goddess who waste no time with those who are unprepared" -
QoS Questions for 3750 Switches
2x3750 switches are stacked and we are trying to simulate traffic congestion at the UTP ports by using Smartbit 6000C. The objective of the test is to see if the QoS setting works in reality even though we see from Wireshark that the packets are marked with DSCP for voice traffic.
Setup is as follows :
Smartbit<->Avaya IP Phone<->3750 switches<->6509 switch.
Please note that the configuration is set on the 3750 switch port as well as trusted on the Cat 6 switch port. However, when I set to continuous traffic with byte size of 64. Even though its a 100Mbps port, the Avaya IP Phone is already acting weird with hanged symptom. Just side note is that performing "show mls qos inter gi2/0/7 statistic" shows that data and voice traffic are marked on the different priority which seemed correct.
1) Is this the right way to test? If not, what should be the correct way?
2) The port that's connected to Smartbit is configured and it seemed that with the continuous traffic, even other IP Phones are hanged even though I have set Smartbit to hit on the IP address of the CAT6 Switch port. This is not normal right as this is supposed to be unicast traffic. Any idea what could be the reason?Hello Brandon,
I understand your concern and how you want to test, but with the VoIP services you need to understand that there are 2 points (telephones if you want) involved. Your local one, where you might have taken all the necessary steps to protect and prioritize your voice traffic, and the oposite end which also need to have the voice packets prioritized.
Now, from your description, I understand that the packets (voice and data) marked correctly (I believe on C3750), but that's not enough. You need to use CBWFQ together with LLQ to give priority to the Voice traffic over data in case of congestion. Do you have such configuration? Can you show us some excerpt from it?
Next, during the testing, you said that your phone hang-up...where you in a call?
To respond to your questions:
1. The start is ok, but we need more details. You are pushing traffic from Smarbit, this is your local end, but where is the traffic pushed to (remote end), who is receiving the traffic?
2. In theory, you shouldn't have any impact over voice if links are 100Mbit, only if you have such a power packet generator that could fill 100Mbit. What do you mean by "This is not normal right as this is supposed to be unicast traffic"? VoIP is also unicast traffic...
I can see that you are determined to solve this issue, and this is OK as it will help you back with gained knowledge, but I have to warn you that troubleshooting QoS / Voice related problems may be more tricky than you think, as it will involve a strong know-how in these areas.
We will help, but you have to come back with more precise details.
Good luck!
Calin -
Hello,
just to put this out there, I am a noob to the world of Cisco, just got my CCNA, and am now working as an intern.
Can you set esw 520 switches to use auto QoS? We are putting the 520's into an environment of more configurable catalyst switches, and they all use auto QoS. I am basically wondering how to get the QoS on the 520's to play nice with the auto qos on the nicer catalyst switches...
I have tried just using basic QoS, but that wont work, because when I use the port wizard, I use the macro "ip phone + desktop"
It insists on setting qos, but fails because voice-map does not exists. The only way I have found to get the macro to work, is to set QoS to advanced, and create a policy map called "voice-map" of course, after that the macro works, but then I am left with advanced QoS enabled, and hardly configured...how am I supposed to know how to configure it if the other switches ( catalyst series) are set to auto?
Im sorry for the seemingly dumb question, but I know next to nothing about QoS other than it is used to prioitize traffic based on data types.Hey cole, typically with theses switches the smartports will do the QOS with the port role, however you can manually create the QOS for the switch, by creating a ACL to identify the specific traffic comming through the switch port. Then Create a class map/ policy map/ and then bind it to the ports your wanting to setup QOS on.
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Good evening everyone
I'm a network administrator and I have been struggling with QoS and I will explain why.
My RV016 is directly connected to the modem and to a gigabit switch as well. there's only one cat6 carrying the traffic to the switch, which is connected to every single device that we have in our network, including IP telephones.
The RV016 provides two types of QoS which is the prioritazation of an application, where I have already configured to prioritize RTP traffic for voice(ports5000-9000). However, if I prioritize the port which carries all my network traffic with a "High"priority, I BELIEVE it will prioritize and tag every type of traffic that is being passed through the wire, making my application QoS configuration completely useless. I had never taken any QoS courses, so I'm just assuming that this is what is going to happen. .
My question here is, if I leave out the port that carries all the traffic with a "normal" priority tag instead of "High" and prioritize RTP traffice through application QoS, will that be enough to prioritize RTP traffic? Or do I need to configure each IP Phone to a port and prioritize the port to high as well to ensure that RTP traffice will be prioritized?
Any help would be highly appreciated. Thanks in advance!Thiago,
Whenever QOS is implemented it has certain criteria in which it has to match or it will not apply the QOS to the frame.
There is port based, where everything that passes through that port will receive the higher quality of service than the other ports.
Then there is protocol or ip based QOS, where if the protocol matches that protocol or port number then it receives the QOS. If it is ip based, it has to match the ip address range you specify to receive the QOS.
So if you have QOS implemented to match those protocol ports, then only if the traffic matches that criteria verbatim will it be applied.
In the Switching world, you have to create acl's to match certain criteria to apply qos. You can say any packet in a certain ip address scheme, matching this protocol port will receive this QOS.
Hope this helps expain QOS a little bit for you. -
Hello, I have SG300-28Ps as the PSE's for my IP telephone system. The phones are tagging their voice packets as DSCP 46 as directed by auto voice vlan. The QoS settings on the switch are at default - Basic Mode, Trust DSCP, strict priority, etc.
On the PBX itself, DB programming allows me to program the 'Type of Service' for the voice packets. The recommended value in the manual was 184 which makes sense, as this decimal value for ToS corresponds to DSCP 46, CoS 5, etc.
The question comes though, do I need to change the trust mode on the switch? I'm not real clear on the differences between them.
Regards,
-BraytonHi Brayton,the trust mode doesn't need to be changed. 802.1p specifies a 3 bit field called a PCP within the etherner frame header when using tagged vlan frames. This will contain a class of service priority.
The CoS is able to map to DSCP values. The DSCP has a 6 bit field called diffserv (differentiated service). CoS values are able to be mapped to DSCP values. Video is generally CoS 4 while voice is generally CoS 5. Within the SX300 you are able to manually set the mapping to any value you'd like. With trust mode, the switch will basically accept and agree with whatever the tagged ethernet frame contains. Without trust mode, the switch will remark the packet based on the PCP and DiffServ value to fit in to the different categories.
-Tom
Please mark answered for helpful posts -
Newb VoIP End to End Qos Questions
I'm at a site that has Layer 3 Cisco switches and routers end to end. Cisco IP phones plug directly into Layer 3 switches with various routers in the core.
1) If all connections are Layer 3 do I need to concern myself with trusing COS? I would trust DSCP in this case yes?
2) Cisco phones by default send voice rtp audio with DSCP marked as EF, is that correct? If not, I know how to create policy-maps and reclassify it. My thought was it is already classified as high as possible.
3) I've read that QoS must be end to end or you don't really have a full implementation, as in the one device your traffic passes through that is not performing QoS will likely be running FIFO or WFQ, which do not give precedence to class based traffic. So in theory I need to implement CBWFQ or LLQ on every Layer 3 device end to end that RTP audio will touch. Do I have this correct?
4) If the voice traffic has the potential to travel to most Layer 3 devices in the network as it travels between the Call Manager and phones, I need to apply QoS outbound on each Layer 3 interface that is likely to be in a voice path yes?
Sorry, I'm a newb, I understand it in theory but I still hit the wall on occassion with my light saber while blindfolded.
Thanks, MikeHi
1) Yep - no trunk (dot1q/ISL) = no CoS as it's in the trunk header, so use DSCP.
2) Yep, traffic will be marked. You can trust it, or trust it conditionally in a service policy and police it.
3) Yep, more or less. It's very important that on any switches that have QoS enabled, you have proper trust states set on all the ports, otherwise the DSCP will be remarked to 0. This is worse that not particularly prioritizing voice on a particular device, as no other devices further down the chain will see any DSCP markings to act on.
4) Erm.. kind of. If it's a layer 3 link on a switch, then you don't configure it as you would on a router. The QoS is done in hardware, so your common/garden autoqos type config should see you right if you really don't know what you are doing. If you use auto qos voip trust, make sure you set it to mls qos trust dscp after as it will probably default to CoS. Best to keep it consistent...
Regards
Aaron
Please rate helpful posts... -
If I don't have any VOIP devices, should I just leave all the QoS settings to default? We have an AirPlay speaker on our network, so could there be benefits in raising the QoS priority so that the audio streams smoothly to this device?
Cheers,
MaxHi MaxHodges, the default QoS will apply to only tag VLAN packet from 802.1p. Otherwise the traffic is treated first in first out basis and switching at hardware speed.
Unless you have a significant amount of traffic that causes congestion there shouldn't be any problem. Separating traffic on a VLAN may logically separate the packets but it wouldn't separate the physical wire usage. So if everything is working as intended then there shouldn't be any need to do anything.
If you are experiencing problems with things like choppiness, you may want to troubleshoot from a congestion point of view such as removing all other traffic off the link and see if its clear or continues to have a problem. At that juncture, if you determine that with additional traffic load causes a problem then it may be prudent to think about a VLAN or reducing the amount of traffic on the un-aggregated link or possibly adding another uplink in to your network.
If the choppiness/quality doesn't clear with just your music box going then chances are it's not the switch or if it's the switch then it'd likely be a wiring issue or doubtfully the switch itself being flaky. -
Hi all,
need some advice here ..
1) for QoS, which one better, configure inside CE or PE
2) Can we do QoS based on time/date. ie end of the month or after 6 pm, e-mail become silver ..other than that, e-mail traffic is precendence 0. And also bandwidth allocation. That means, middle of the month, gold is 40% and end of the month, gold is 15 %.
If yes, any good link/url for this. I think it can be done but just wanna get opinion/advice from u all.
rgds,
--mdshahYou can use the modular QoS CLI to achieve this. You can create time based ACLs and use them in the policy-maps to set IP precedence or other parameters like MPLS EXP bits or DSCP values, based on which QoS treatment can be given to the traffic. Check out the 'Classification' and 'Modular QoS CLI' setions in this link :
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/index.htm -
Cisco 1602e AP bandwidth limiting, qos question.
I have a few AIR-SAP1602E-A-K9, and I was wondering if they are able to do any type of QoS or bandwidth throttling/limiting based on destination ip address or perhaps even just limiting the speed of that wireless interface? Essentially we'd like it so people on the "Internet only" ssid can use a certain amount of bandwidth - like 4mb or something. If this AP simply can't do it, then are there any suggestions for what I should do instead? Thanks in advance for any assistance!
You have an autonomous AP and its really not possible to limit the traffic. You might be able to setup am acl on the router to limit the bandwidth as long as these users are on a different subnet than your internal user. Others in the past have used a 3rd party wifi hotspot software. These software you can have users login or not, but you can control bandwidth. Some are paid versions and some are free. You would just have to look around and try them.
Sent from Cisco Technical Support iPhone App -
As my understanding, WiSM enforce QoS at the controller level, not at the AP level. For example, I set average rate to be 1Mbps and the user generate 50Mbps traffic. The traffic still used up the AP bandwidth and is throttled at the controller. Will it cause congestion at AP level?
ZhenningQoS is enforced both at the AP level and controller level.
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Hello,
I am trying to upgrade from 3750 to 3850. Following is my outbound WTD qos config on 3750:
mls qos srr-queue output cos-map queue 1 threshold 3 5
mls qos srr-queue output cos-map queue 2 threshold 1 2 4
mls qos srr-queue output cos-map queue 2 threshold 2 3
mls qos srr-queue output cos-map queue 2 threshold 3 6 7
mls qos srr-queue output cos-map queue 3 threshold 3 0
mls qos srr-queue output cos-map queue 4 threshold 3 1
mls qos srr-queue output dscp-map queue 1 threshold 3 46
mls qos srr-queue output dscp-map queue 2 threshold 1 16 18 20 22 32 34 36 38
mls qos srr-queue output dscp-map queue 2 threshold 2 24 26 28 30
mls qos srr-queue output dscp-map queue 2 threshold 3 48 56
mls qos srr-queue output dscp-map queue 3 threshold 3 0
mls qos srr-queue output dscp-map queue 4 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 3 4 10 12 14
mls qos queue-set output 1 threshold 2 70 80 100 100
mls qos queue-set output 1 threshold 4 40 100 100 100
What will be the equivalent config for the 3850? I am not able to find the right documentation for 3850.
Following is what I created but I believe it wouldnt handle WTD.
class-map match-any EF
match dscp ef
class-map match-any CS3AF41
match dscp cs3 af41
class-map match-any AF21
match dscp af21
class-map match-any AF11
match dscp af11
class-map match-any Default
match dscp default
policy-map QOS-OUTBOUND
class EF
priority level 1
class CS3AF41
priority level 2
class AF21
bandwidth remaining percent 20
shape average percent 100
class AF11
bandwidth remaining percent 20
shape average percent 100
class Default
bandwidth remaining percent 60
shape average percent 100
Also, when I try to apply this to an interface, it accepts it but its not visible under show runn. Am I missing anything?
I would appreciate any help with this.
Thank you.Hi,
3850 is not supporting MLS QoS (so any QoS commands start with mls keyword is not applicable in this switch platform- even thoug they are accepted).
It is a MQC QoS based switch platform (like 6500,4500). There are few Queing models (1P7Q3T, 2P6Q3T for wired & 2P2Q for wireless) supported in this platform. Please refer below post for more detail
http://mrncciew.com/2013/12/23/3850-qos-part-2-queuing-models/
Based on this you need to derive your config changes. As you can see in the above "queue limit x " is the command used to configure WTD for non-priority queues (ie Q2 to Q6)
Regarding running config, you can use "show running-config all" command to see all the configuration lines of your switch including default configs
HTH
Rasika
***Pls rate all useful responses **** -
ESW-520-48 QoS question - config snippet
Hello,
Can someone give me a sanity check on this config? It is from an ESW-520-48. This is my first time see one and it looks a primitive version of IOS. There are some QoS policies defined but I don't see the correct policies applied and it doesn't look any of the VoIP policies are nested either. In standard IOS, the nested policy is indented. Is there any QoS applied in this config?
Snippet:
ip access-list 2140
permit any any any
exit
ip access-list 2141
permit any any any dscp 46
permit any any any dscp 40
exit
ip access-list 2142
permit any any any dscp 24
permit any any any dscp 26
exit
ip access-list 2146
permit any any any
exit
mac access-list nonip
permit any any ethtype 806
permit any any ethtype 836
exit
class-map general-class match-any
match access-group 2140
exit
class-map general-switch
match access-group 2140
exit
class-map general-router
match access-group 2140
exit
class-map VoIP-data-class
match access-group 2141
exit
class-map VoIP-Control-class
match access-group 2142
exit
class-map general-VoIP
match access-group 2140
exit
class-map general-nonip
match access-group 2140
exit
class-map video-surveillance-class
match access-group 2146
exit
class-map nonip-class
match access-group nonip
exit
policy-map general-map
class general-class
set dscp 7
police 30000 80000 exceed-action policed-dscp-transmit
exit
exit
policy-map switch-map
class general-switch
exit
exit
policy-map router-map
class general-router
exit
exit
policy-map voice-map
class VoIP-data-class
set dscp 46
police 3200 8000 exceed-action policed-dscp-transmit
exit
class VoIP-Control-class
set dscp 26
police 640 8000 exceed-action policed-dscp-transmit
exit
class general-VoIP
set dscp 7
police 30000 800000 exceed-action policed-dscp-transmit
exit
exit
policy-map video-surveillance-map
class video-surveillance-class
set dscp 40
police 50000 800000 exceed-action policed-dscp-transmit
exit
exit
policy-map guest-map
class general-nonip
set dscp 8
police 30000 800000 exceed-action drop
exit
class nonip-class
exit
exit
interface ethernet e1
service-policy input switch-map
exit
interface ethernet e18
service-policy input switch-map
exit
interface ethernet e24
service-policy input router-map
exitHey cole, typically with theses switches the smartports will do the QOS with the port role, however you can manually create the QOS for the switch, by creating a ACL to identify the specific traffic comming through the switch port. Then Create a class map/ policy map/ and then bind it to the ports your wanting to setup QOS on.
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Before I buy this thing. Can you create your own QOS policy, or does it only do automatic QOS?
Hi !
For tht u will need to keep checking with linksys.com !
Network Security Administrator (EC Council)
linksysfirmwares.googlepages.com/ -
Hello world!
I want to enable qos on a 3560 switch,
So, I put:
Overall setup mode "mls qos"
Question:
is what it is Verily nessaiire to interface configuration mode: "mls qos trust"?
Regards,Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
Generally, on many Catalyst switches, once you enable QoS, they will erase an ingress CoS/ToS markings unless your trust it or otherwise (i.e. policy) maintain it.
I.e. the answer to your question is an "it depends"; but unless you want the markings reset to zero, the answer is probably yes (you want to trust).
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