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May 16th, 2008
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Welcome to the Cisco Networking Professionals Ask the Expert conversation. This is an opportunity to learn how a Cisco Catalyst switching architecture can optimize, secure and scale video in you LAN network with Cisco expert Aziz Abdul. Aziz is a Senior Technical Manager, Enterprise Systems Engineering with Cisco. His focus is on business networks in the areas of IP network design, emerging technologies including video and voice over IP, and related collaboration tools. He has been with Cisco for more than 11 years and led many software development and network design engineering teams. Aziz has more than 15 years of broad experience in IP networks including design and implementation of large service provider broadband access networks, service provider television alternatives, and wireless and mobility design for enterprise networks.

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Aziz might not be able to answer each question due to the volume expected during this event. Our moderators will post many of the unanswered questions in other discussion forums shortly after the event. This event lasts through May 30, 2008. Visit this forum often to view responses to your questions and the questions of other community members.

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Overall Rating: 4.4 (12 ratings)
vishal_maniar Mon, 05/19/2008 - 07:04
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i have 2 2821 Routers can the built in Gigabit Ports on the routers be configured as EtherChannels ???

aabdul Mon, 05/19/2008 - 12:56
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Cisco IOS Release 12.4(17.6) supports EtherChannel for embedded Fast Ethernet and Gigabit Ethernet interfaces on Cisco 2800 and 3800 series routers - includes the 2821 that you are interested in.

michaelseare Mon, 05/19/2008 - 11:05
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I have cisco 4948 10Gig 48 port switch and would like to use it for internet to support about 25 users in my compacny.I have another core switch that is a foundry 9604. how woutd I configure and connect this cisco router to this foundry. Explain me or send me the configuration sample from the cisco 4948.


aabdul Mon, 05/19/2008 - 13:07
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If you use the right optics to connect the two devices and configure standard versions of L2/L3 protocols (spanning tree/OSPF) you should be fine.

Note that EIGRP may be used only if you are using two Cisco devices. Further information on EIGRP/OSPF including configuration examples can be found at:

A Cisco Cat6500 switch on the other hand would make your distrubution-core connection much more robust. More on Cat6500 at:

agroarke Tue, 05/20/2008 - 02:04
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I am configuring Qos on 3560 2960 and a 6500 using 6148-GE-TX and 6724-SFP line cards

The problem I have is 3560 and 2960 support DSCP mapping to queues and allow mls qos trust DSCP but the line cards in the 6500 only alow mls qos trust the 6148-GE-TX line card uses 1P2Q2T and the 6724-SPF uses 1P3Q8T.

I am trying to implement QoS for voice multicast and IPTV, do I only use COS or a mixture of Cos and DSCP could you please help with some configuration guidelines

Pravin Phadte Tue, 05/20/2008 - 02:53
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The cisco express 500 series swithes seems to have a lot of drawbacks with the kind of deisgn and arch they have.

1. No telnet option.

2. Concept of smartport (it has a option to recomend which option is best and it would choose as we did. Funny)

3. If a cisco WLAN controller is connected to any of the ports it does not recorgnize the device.

I have worked with diffrent vendor swithes but never seen a switch with no telnet option.

The switch performace is good.On a part of cnfiguration it seems to a bit troublesum.

Will cisco release some new firmware to support telnet and correct more option on the 500 switch ?

aabdul Tue, 05/20/2008 - 10:36
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Cisco Catalyst Express 500 Series Switches can be managed either through the embedded Device Manager or with Cisco Network Assistant.

I am not aware of any plans to add CLI or telnet to these switches.

for issues related abnormal behavior with WLAN, etc., please open a case with Cisco TAC.

Feel free to post further questions related to Video in the Entreprise on this forum.

aabdul Tue, 05/20/2008 - 10:19
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We recommend trusting DSCP on all platforms that support it. The CoS-to-Queue mapping limitation of the 6500 should not be a gating factor.

For QoS configuration guidelines and examples you may want to refer to the QoS Design Guide at:

Also, though you are not interested at Telepresence, you may want to look at Telepresence 1.1 SRND (chapter 4) on additional options and guidance on the CoS-to-Queue limitations for some general understanding. This design guide is also available at the above URL.

agroarke Wed, 05/21/2008 - 04:57
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I have had a look at the telepresence SRND and have used it as a template. The 6500 cards will not take the config unless you trust COS on the interfaces.

Also why does the config when selecting an interface on the 6148-GE-TX say gi2/1 apply it to the range gi2/1 -24 and with the 6724-SPF (24 port) apply it to the range gi2/1 -12 instead of the individual interface?

aabdul Wed, 05/21/2008 - 10:17
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There are two port-trust options on the C6500 that can be configured once QoS is enabled (trust DSCP or trust CoS). One needs to be aware of the relationship and consequences of trusting one over the other.

Not sure what is meant by "The 6500 cards will not take config..." what config will it not take?

As for the second question about the range of applied ports: these queuing policies are applied to hardware ASICS, which control a group of ports (sometimes 4, other times 8 -- depending on the linecard). The way the hardware is engineered is that whatever policies are applied to one (or more port) on an ASIC will be applied to all ports on the same ASIC.

For further assistance on this we have to look into your specific issue. You can send your configs, IOS versions, chassis/line card details at [email protected] or preferrably work through your local Cisco account team.

agroarke Wed, 05/21/2008 - 12:14
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thank you for your help it is beginning to make more sense now as on the 6148 card it is 24 ports and on the 24 port card it is 12 ports. I will send you copies of the config in the mean time the error states that the config will not be placed in hardware unless the ports are set to mls qos trust cos

agroarke Thu, 05/22/2008 - 04:38
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Here are the configs I spoke about in my earlier e-mail



interface GigabitEthernet x/y


interface GigabitEthernet x/y

rcv-queue cos-map 1 1 0 1 2 3

rcv-queue cos-map 1 2 4 5 6 7


wrr-queue queue-limit 40 30

wrr-queue bandwidth 40 30

wrr-queue random-detect min-threshold 1 40 80

wrr-queue random-detect max-threshold 1 80 100

wrr-queue random-detect min-threshold 2 70 80

wrr-queue random-detect max-threshold 2 80 100

wrr-queue cos-map 1 1 1

wrr-queue cos-map 1 2 0

wrr-queue cos-map 2 1 2 3

wrr-queue cos-map 2 2 6 7

priority-queue cos-map 1 4 5


6724-SFP Card


interface GigabitEthernet x/y

rcv-queue cos-map 1 1 0 1 2 3

rcv-queue cos-map 1 2 4 5 6 7



interface GigabitEthernet x/y

wrr-queue queue-limit 5 35 30

priority-queue queue-limit 30

wrr-queue bandwidth 5 35 30

wrr-queue random-detect 1

wrr-queue random-detect 2

wrr-queue random-detect 3

wrr-queue random-detect min-threshold 1 80 100 100 100 100 100 100 100

wrr-queue random-detect max-threshold 1 100 100 100 100 100 100 100 100

wrr-queue random-detect min-threshold 2 80 100 100 100 100 100 100 100

wrr-queue random-detect max-threshold 2 100 100 100 100 100 100 100 100

wrr-queue random-detect min-threshold 3 60 70 80 90 100 100 100 100

wrr-queue random-detect max-threshold 3 70 80 90 100 100 100 100 100

wrr-queue cos-map 1 1 1

wrr-queue cos-map 2 1 0

wrr-queue cos-map 3 1 2

wrr-queue cos-map 3 2 3

wrr-queue cos-map 3 3 6

wrr-queue cos-map 3 4 7

priority-queue cos-map 1 4 5

Again as i said in my earlier e-mail when these configs are applied to the respective cards and error appears stating that config will not be applied in hardware until the interfaces inquestion are set to mls qos trust cos

Therefore is it ok to set all ports to trust cos.

I have looked at autoqos voip and this sets the interfaces to trust cos.

Also is it ok to set one end of a link to trust cos and the other to trust DSCP.

In all cases we are talking about 100Mbit/s and 1gigbit/s ports and uplinks.

aabdul Fri, 05/23/2008 - 00:46
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Q: Is it ok to set all ports to trust CoS?

Any port can be set to one of three main trust states:

1) trust CoS,

2) trust DSCP,

3) untrusted

So, of course, any and all ports can be set to trust CoS.

However, the tradeoff in trusting CoS markings (as explained in the QoS SRND) is that marking granularity is limited to 8 values only (0-7); if more marking granularity is needed, then the platform/linecard will not be able to distinguish between codepoints (DSCP values) sharing the same CoS values. For example, if Desktop Video Conferencing is marked AF41 (34 or 010010) and TelePresence is marked CS4 (32 or 010000), both share the same CoS value of 4 (i.e. the same first three bits of marking are identical), and therefore these different applications cannot have different QoS policies applied to them, as they are indistinguishable from a CoS-perspective. This is why, in general, we recommend trusting DSCP within the campus interswitch links and core links. At access ports, the administrator can choose to trust DSCP or CoS (or leave the port in an untrusted state).

Q: is it ok to set one end of a link to trust cos and the other to trust DSCP?

Yes that is fine.

Q: why the error message?

The reason the parser is barking that the interface can only be applied if the port trust setting is changed to 'trust cos', is because this is a non-default ingress CoS-to-Queue mapping. The 6148-GE-TX has a 1Q2T ingress queuing structure, with the default settings documented at:

So, in this non-default config, CoS 4 is being mapped to Q1T2 (instead of the default mapping of Q1T1). For ingress queuing policies to be modified away from default, the port has to be configured to 'trust cos', which is exactly what is happening.

Hope this helps. Please contact your local Cisco account SE for further assistance if the above does not solve your specific issues/concerns. Thanks.

agroarke Fri, 05/23/2008 - 05:40
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Thanks for your help but if these configs are good enough for telepresence then they are good enough for me maybe I am making things more difficult than they really are



chungrod1 Tue, 05/27/2008 - 09:22
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I have a customer who has Cisco 3825 router with the boot config on a 256MB flash card and the problem is that the admin password has been misplaced.

Is there a means of recovery the password or at worst resetting the flash card/router to factory defaults?

Many thanks in advance.

gmobilegungaa Tue, 05/27/2008 - 22:22
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How to look cisco 7200 series router price list

Yours sincerely,

Gungaa, from Mongolia

aabdul Tue, 05/27/2008 - 23:27
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Your best bet is to work with a local Cisco partner that can help with correct product configuration and pricing.

You can search channel partners for your city/country at:

Feel free to write back with specific questions related to planning and implementing Video solutions using Cisco products on this forum.

noel.m Thu, 05/29/2008 - 11:49
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We are preparing to implement a large scale video network on our tollroad with over 200 cameras - and there is a concern that we will not have enough bandwidth to handle traffic.


Over 90 cameras on 10 encoders connected to three 2960 switches using a ZX 1000 fiber link to the main site. (This is just one site - to get the complete scenario multiple by three each using their own fiber to connect to the main site)

Depending on speed and resolution - each camera (per sales) is suppose to use 3.75 to 4.25 bytes per video stream -

In my calculations, a gig of bandwidth can handle this load. (using unicast)

Do you concur, and/or what am not taking into account.

How much will we save in bandwidth using multicast.

There is a concern that even using a webserver to view the cameras, that if we had 10 executives viewing the cameras, that we will over load link. Is this true with unicast? Is this true with multicast?

noel.m Thu, 05/29/2008 - 12:17
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Correction 3.75 to 4.5 megabits per video stream - Thank you, Noel

aabdul Thu, 05/29/2008 - 17:44
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