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Questions tagged [qos]

For questions about Quality Of Service (QoS); all aspects of providing differential service to packets based on TOS, DSCP, or other information.

27
votes
5answers
21k views

Are CoS and QoS ever interchangeable?

The terms CoS & QoS are often used interchangably, particularly in the SP space when providing "Class of Service profiles" etc as part of Product sets. I'm looking to re-affirm my understanding ...
22
votes
10answers
23k views

How to generate traffic for lab scenarios [closed]

I'd like to start exploring QoS, and lower level optimizations for things like broadcasts/multicasts within my home lab. I've looked around for ways to generate traffic to and from a box, but haven't ...
16
votes
3answers
3k views

class-default matches control traffic?

I'm seeing an issue with BFD on a link that's being policed egress where it appears during times where the policer is maxed BFD packets are not getting to the other side. I'm wondering if BFD hellos ...
15
votes
7answers
3k views

Quality of Service based on Layer 7 traffic [closed]

How can one perform quality of service based on layer 7 traffic? How would you classify the traffic and actively monitor and respond (dynamically prioritizing traffic)? Are there any solutions which ...
14
votes
4answers
4k views

Enabling MLS QoS on a production 7600

I am looking at a 7609-S with a RSP720-3CXL running 12.2(33)SRE3. I have been asked to help with rate limiting some servers attached to a couple of ports running as L2 ports (switchport mode access), ...
13
votes
1answer
12k views

What is the 5 level QoS model (through config example)?

I have heard people stating that their network "operates a 5 level (or layer) QoS model" Sometimes they also mention a 7 level QoS model. Can anyone provide me with a Cisco IOS config example of ...
13
votes
2answers
21k views

How can I verify QoS DSCP marking on a Cisco Catalyst 4500E?

Good afternoon, I've got a shiny new 4500E running 15.0(1r)SG7 that is set to replace an ailing 3750E. It is running ipbase for now. On the 3750 I was able to check out the incoming DSCP/CoS values ...
11
votes
6answers
6k views

Weather map and monitoring for network usage [closed]

What tools are able to provide an almost real time weather map of usage and average traffic per timeframe going over the different links? What are some ways or solutions to actively monitor my ...
11
votes
1answer
543 views

enforcing QoS on a “variable” speed link where the negotiation is done by the carriers NTE

In essence we purchase a 80/20 line from the carrier who provides the transport between the customer premises & the local exchange where the carrier terminates into our PE. (Juniper PE) <--> [...
10
votes
2answers
11k views

How do you throttle Dropbox Traffic?

It appears that Dropbox uses Amazon AWS for it's storage, so I am not able to just block or trottle traffic to dropbox.com Since there are a lot of web services that rely on AmazonAWS, I cannot just ...
10
votes
1answer
1k views

Does IP provide QoS or not?

IP provides a best-effort delivery service. I believe this implies, among other things, that it offers no QoS to the users. However, IP has a byte in its headers (ToS in v4 and Trafic Class in v6) ...
10
votes
1answer
2k views

QoS between two VLANs with Cisco 881 Router (IOS)

I'm hoping to get some advice regarding the best practice to delegate a limited Internet connection between two VLANs. In my case, one VLAN is for an office network, and the other is for guests. What ...
10
votes
1answer
33k views

How can I reasonably verify my QoS configuration is working?

Context I've deployed a standard QoS config to a customer site running a Cisco 891 router with IOS 15.1(4)M4. The WAN link is a single ADSL2+ link (24/1Mbps) connected to FE8. I've previously tested ...
9
votes
4answers
735 views

How does one specify certain IPs or MAC addresses for NBAR policy enforcement?

In an office environment, if I wanted to block youtube using a Cisco ISR router, I would set up the following with NBAR: class-map match-all YOUTUBE match protocol http host "*youtube.com*" ! policy-...
9
votes
3answers
7k views

How are Weighted Fair Queuing and Weighted Random Early Detection related?

I'm trying to understand how QoS systems work and I'm not sure how exactly would WFQ and WRED interact. At first, I thought that WFQ is a queuing mechanism and that WRED is a congestion avoidance ...
9
votes
2answers
2k views

QoS woes - managed IP VPN

(First of all, I'm sorry for this wall of text. I don't know how to make it any shorter without losing important information. I originally wanted to use the chat room for this, like we do on ...
9
votes
2answers
1k views

Which QoS classification should be applied to NTP?

Cisco's Enterprise QoS Solution Reference Network Design suggests classifying NTP as network management traffic and marking it as CS2: When addressing the QoS needs of Network Management traffic, ...
8
votes
3answers
4k views

Traffic Policing

I know traffic policing isn't something that you normally find in a LAN environment, and I wish I wouldn't be finding it in mine. That being said... I have no choice. The device is a 3750X. The ...
8
votes
3answers
4k views

Implementing Cisco QoS model to end users

I have implemented the 4-Class QoS Model as described in this earlier post from 2013. This Core configuration is implemented on a Cisco VSS 6509-E setup running software version: Cisco IOS Software, ...
8
votes
2answers
122 views

TDMoE and QoS considerations

As mentioned in the previous question I am looking at sending voice communications over a Metro Ethernet connection shared also by data connections. In addition to the previous question I have this ...
8
votes
4answers
508 views

QoS on a dedicated VOIP network

Is there any point in enabling QoS on a dedicated VOIP network that only has VOIP traffic?
8
votes
1answer
2k views

Globally disable QoS on Cisco 3750 in production

I suspect some issues with faulty QoS settings on a 3750 stack running in a 24x7 environment. The 3750 mainly routes between vlans on a lan segment. Since it is a lan device (not terminating any wan ...
8
votes
2answers
1k views

Basic Catalyst 3560 Egress Shaping

We have a service provider (and we can't change providers) who is giving us a "metro ethernet" style connection between two of our locations. On each end, we plug into an ethernet port on a provider's ...
8
votes
2answers
1k views

QoS Video - I want to prioritise video traffic. What protocols and port numbers should I add to my QoS design?

Can someone please tell me what protocols and port numbers I need to add to my Prec 5 DSCP QoS configurations to ensure that any video traffic gets pushed out first if there is congestion. Is it just ...
8
votes
1answer
599 views

Ethernet switch capable of H-QoS at the 802.1q level

I have the following type of links at the edge of my ISP cloud: +-----------------------+ ...
7
votes
1answer
7k views

Auto-QOS configuration for Cisco network

I have a network with Cisco switches, Cisco IP Phones and video traffic. I want to add QoS markers to my traffic but I don't want to do it manually. Ideally I want to use Cisco's auto QOS features ...
7
votes
1answer
230 views

Throttling among Data Centers

In general, links among data centers are shared (having shared network infrastructure). Thus, I can't detect the available bandwidth in between two data centers that may vary every while and through ...
7
votes
1answer
263 views

How is probabilistic marking performed with Random Early Detection?

I am currently studying for my Computer Networks exam. I cannot wrap my head around the following. When the current Average Queue Length is in between a min_threshold and a max_threshold, the Random ...
7
votes
2answers
830 views

DSCP trust boundary

I have performed some analysis and noticed that traffic coming in from the Internet contains a myriad of DSCP values. This traffic competes for voice and video resources on the internal network. How ...
6
votes
3answers
1k views

Is QoS an issue for VOIP calls over the Internet? If not, why not?

I'm trying to decide whether I should buy SIP trunks from my ISP or a 3rd-party. As I understand it, it's important to maintain QoS on an internal network (i.e. prioritize VOIP traffic). Is this not ...
6
votes
3answers
372 views

QoS at the edge of branch

I have a question about QoS design in branch. The main place to deploy qos in branch - edge between edge router and ISP. At this edge we have voice traffic to SIP provider, copr. external email and ...
6
votes
2answers
6k views

QoS on HP Procurve 2520 and 3800 switches

Do Procurve switches remark cos/dscp values between switches (trust boundaries) as Cisco switches do? I'm wondering if there is an equivalent to "mls qos trust (cos/dscp)" in the HP realm.
6
votes
2answers
446 views

Metro Ethernet settings on Customer devices

I am about to connect three remote sites to the main office by means of an metro ethernet provided by a service provider. The sites are connected by means of l3 and running OSPF on the connecting ...
6
votes
3answers
4k views

How to throttle speed for a particular computer with high activity?

We're in an office environment of about 50 people. A few departments send emails with large attachments extensively and doing so clogs up the WAN connection (10Mbps). I'm upgrading the networking ...
6
votes
1answer
239 views

Why there is a maximum of 4096 queues in WFQ?

In QoS there is a variety of Queuing methods and one of them is WFQ, which organizes the flows in different queues where each queue has a weight that determines which flow will go first. Now for ...
6
votes
1answer
3k views

TX-ring-limit Values

So, I am getting deep into my CCIE study and I just read about the TX-ring-limit interface command. I have used QoS a bit to oversubscribe software buffers to prevent frame loss on switches and ...
6
votes
1answer
3k views

What is benefit of using CBWFQ with fair-queue statement

I mostly seeing configuration of QoS queues based on CBWFQ, witch is tripped off by shaping map. Something like below example. policy-map test class test bandwidth remaining percent 20 random-...
5
votes
2answers
8k views

ISP edge router configuration

I need to configure Cisco 2901 router to route between interconnect block and usable ip block. Circuit is fiber 30Mb/s I got this info from ISP provider: IP space: Interconnect block - 50.204.xxx.80/...
5
votes
2answers
4k views

How do I tag traffic with a DSCP value on an ASA?

I have a SIP Server that does not put a DSCP code on it's traffic. This server is behind an ASA, and I want to prioritize its traffic passing through an ASA from the private to public network. I am ...
5
votes
2answers
3k views

Minimum Bandwidth Guarantee 3750-X

I am about to implement a network at a remote office that will also be providing some bandwidth to a sub tenant. We have a 50 Mbps connection terminating to a VLAN on a 3750-X. Each company has an L2 ...
5
votes
2answers
351 views

QoS shaper, shapes traffic without dropping packets?

I have a problem with my QoS policy, or I should better say, I have a problem understanding how my policy manages to achieve what ask of it without dropping a packet! Here is the scenario: We have ...
5
votes
1answer
451 views

Downstream QoS Feasibility

I work for a VoIP provider, and one of the biggest hassles I deal with is downstream traffic management. Our flagship product is QoS-enabled bonded T1 or SHDSL bundles configured to support our own ...
5
votes
1answer
7k views

QoS voice traffic on WAN of Cisco 1841

I have the following lab topology and I am using the below configuration on the 1841. What I want to achieve here is reserve 1000Kbps of bandwidth for traffic between the voice VLAN and the remote ...
5
votes
2answers
5k views

Limit egress traffic 2960G

This is to support a user who has the requirement of simulating specific speeds for download/upload. We have configured a limit using service-policy that as successfully limiting upload speed (...
5
votes
1answer
833 views

Is it possible to shape and queue on a switched port in a cisco 4506-E?

Background I have a cisco 4506-E with a sup 7L-E running IOS-XE 03.04.03.SG. The switch is connected to a 150 Mbps circuit via 1 Gbps ethernet port. The port is configured as a switched access port....
5
votes
1answer
968 views

Juniper destination based CoS

I'm trying to do destination based CoS on Juniper MX basing on destination ASN. I've tried config below. set policy-options as-path BGP-PATH-TO-MARK-COS "65512 .* set policy-options policy-statement ...
5
votes
1answer
829 views

ASA Traffic Shapping on a burstable circuit

I am connecting to a 100Mbit WAN circuit, that is Burstable to 500Mbit. If I am going to use ASA traffic shaping on this, would I set the shape average to 100Mbit or 500Mbit? My main concern is ...
5
votes
1answer
217 views

VoIP QoS over DIA/L3VPN physical circuit

This Q. is really confirmation to what I already suspect. On a single physical interface with a carrier that uses two dot1q logical sub interfaces to handle DIA and L3VPN, I suspect any usage of DIA ...
5
votes
1answer
459 views

Cisco 7604 + RSP720 3CXL + WS-X6704-10GE QOS marking problem

Cisco 7604 + RSP720 3CXL + WS-X6704-10GE, need to understand how much traffic from the client comes to external resources, and how much goes to internal network resources. Mark incoming traffic to ...
5
votes
1answer
65 views

Cisco ISR - Police & burst

We have a Cisco C2900 ISR here, with the following configured: policy-map XX_4M _IN police rate 4000000 burst 400000 conform-action transmit exceed-action drop The policy-map is applied on an ...