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.

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200 views

What is the difference between Cisco's QoS models and strategies?

I have been reading about QoS and different strategies. From what I understand, Cisco proposes three different models and three different strategies for QoS. For strategies, you can have a 4-class, ...
3
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1answer
68 views

What is the advantage of Supervised Machine Learning over Deep Packet Inspection in Network Traffic Classification?

As per the definition of Deep Packet Inspection (DPI), it uses signatures for packet filtering. Supervised Machine Learning can help put a label on a packet which does not get identified by Deep ...
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3answers
61 views

High Throughput on BGP Multihomed Network

I've One site connected to my server location via BGP over MPLS and at my server location 2 edge routers cater these WAN links, and are further connected to Servers via switches. Now, Is it possible ...
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13 views

What is the difference between meters and queues in Openflow?

I'm new to OpenFlow and have just started studying Software Defined Networking. I have found a multiple websites mentioning that queues and meters are complementary to each other, and that they should ...
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0answers
64 views

HTTPS QOS and policing [closed]

In our office, everything runs on HTTPS. We have softphones and web-based clients which are high priority. We also have Google search, maps and other low priority websites that should work on best-...
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0answers
39 views

Applying DSCP to an interface

I'm trying to apply DSCP (AF41) to an interface eth-trunk (if it matters) - [~HUAWEI] diffserv domain QoS \ creating diffserv domain named QoS [~HUAWEI] dsdomain QoS] ip-dscp-outbound af4 ...
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1answer
98 views

Cisco qos, service-policy on output interface on 1100 ISR seems ignored

I am trying to configure QoS for a specialty purpose application, and it is the first time I have done QoS. This is on an 1100 ISR with IOS XE 16.09.03. The device is a set of 4 that establish a mesh ...
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1answer
153 views

Unable to see packet drops on tunnels

I have the following topology set on AWS where there are 4 CSR 1000v Routers deployed and Segment Routing enabled in which the Segment Routing Headend is R1 and the destination is R3. I aim to send ...
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45 views

Packet scheduling in LTE/5G core network components

Scheduling algorithms must be used in radio side of these technologies in order to map radio sources to incoming/outgoing data packets and satisfy quality of service requirements such as latency and ...
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0answers
70 views

I'm unable to see packet drops after configuration of QoS policy

I aim to send iperf traffic from Endpoint1(Client) to Endpoint2 (Server) with the following SR path = {R1, R2, R3, R4, R3, R2, R1, R2, and R3}. First of all, the traffic generated by iperf from ...
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54 views

Cisco Catalyst QoS queuing model

How Cisco Hardware queuing model (like 1p7q4t for Cat6800) are related to traffic classes (class-map) ? How assign the X traffic class to Y hardware queue ? Also, if only 6 classes are configured, ...
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1answer
64 views

Suggestion for Weights for Weighted Round Robin

I have looked over the book "End-to-End QoS Network Design" by Tim Szigeti et al. and RFC4594. The RFC proposes 14 Service class: I have a switch with simple QoS features. It has 14 egress queues on ...
3
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1answer
183 views

STP packets and QoS

Routing protocol packets are IP packets and therfore they could have different DSCP values to have different priorities (which is implemented by QoS policy) during congestion. How about non-IP packets?...
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1answer
93 views

Network Control Packets and QoS

In RFC 4594, titled as "Configuration Guidelines for DiffServ Service Classes", it is suggested that network control packets should be tagged by DSCP 48 (CS6). Protocols like OSPF, EIGRP, ISIS and so ...
2
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1answer
210 views

Cisco nexus 9396PX TX output discard on 40G interface without link congestion

We have cisco nexus 9396PX with N9K-M12PQ module (12x40G Interface), We have 8x10G L3 LACP bonded connectivity with our ISP and so far so good no issue at all. but recently we migrated that LACP LAg ...
2
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1answer
234 views

Do unmanaged switches honour QoS priorities set by managed switches?

Details about the devices We have a 24 port NETGEAR managed POE switch that has QoS capabilities. We also have the following unmanaged switches, 24 port Cisco POE, 48 port Cisco, 48 port NETGEAR, ...
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2answers
475 views

Trust dscp command missing on cisco 3850

We have an incoming QoS configuration on our 2960X switches like this: class-map match-any QOS_GL_TRUST match ip dscp 8 16 24 32 46 class-map match-any QOS_GL_CITRIX match access-group name ...
2
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1answer
115 views

QoS - Add DSCP EF tag with L2 switches?

Here is the topology that I have: Phone => (access port) L2 Switch (trunk) => Router My goal here is to add an EF tag to the packets coming from my phones. Basically, if a packet comes in being in ...
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0answers
16 views

Why in DRR (Deficit Round Robin) is the Deficit Counter set to 0 when the list of packets for a flow gets empty?

I'm studying DRR scheduling algorithm (https://www2.cs.duke.edu/courses/cps214/spring09/papers/drr.pdf) but I don't understand why the deficit counter is always reset to 0 when the list of a flow get ...
2
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2answers
98 views

C3PL working order

It is very hard to find information on this topic. I would like to know: If traffic has a hit inside a class-map, is it immediately forwarded or does it get checked against all remaining match ...
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1answer
72 views

Fair-queueing every class within CBWFQ

My question is similar to: What is benefit of using CBWFQ with fair-queue statement Given this policy-map (without class-maps) configuration: policy-map test class DSCP30 bandwidth percent 20 ...
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1answer
71 views

qos inside vpn, possible or not ? I read yes and no

I am wondering if possible to do QOS (or similar action) inside vpn tunnel to a cloud server. the goal is to reserved bandwith for voip traffic. I read that you can with GRE and other people said, ...
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1answer
571 views

Cisco QoS SRR Share & Shape impact

I am working on understanding the impact of using shaping and sharing with the SRR scheduler. Given these 2 commands on an interface: switch(config-if)#srr-queue bandwidth share 40 20 30 20 switch(...
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1answer
34 views

QoS Classification and Drop Rate

Sorry if i sound completely senseless, In CBWFQ, q1) Does WRED only make sense if there is more than 1 dscp marking in a queue ? q2) if traffic_typeA is to be handle with higher priority then ...
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1answer
129 views

QoS on 2960X does not seem to have an impact

We have some issues with Dect stations that have a very high requirement in regards of delay. Communication between 2 devices should not exceed 500 microseconds (0.5ms). We decided to test some ...
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1answer
138 views

CISCO Tc Bc and CIR units

Are the units in these formulas correct? Tc (seconds) = Bc (bits) / CIR (bits per second) Tc (milliseconds) = Tc (seconds) * 1000 Bc (bits) = Tc (seconds) * CIR (bits per second) CIR (bits per second)...
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1answer
29 views

Access and uplinks ports QoS Queuing model

On an access switch, does the uplinks egress QoS Queuing model (multiple traffic classes and bandwidth reservation), should be different than the access ports egress Queuing model ? Is there a sense ...
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2answers
95 views

what is the difference between OpenFlow queue and 802.1p

I was reading about queues and I came across OpenFlow Queues and IEEE 802.1p I would like to know what are the main differences between them, and how they treat the traffic. In other words how they ...
2
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1answer
35 views

Is WRED configured for TCP traffic only?

I am looking out for a practical usage of WRED. After reading/searching I found that it is more suitable for TCP traffic. When the queue is full, all the TCP session at that time will start with slow ...
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2answers
450 views

How to block youtube url on a cisco router

How can i block youtube on a cisco router? I have already used class map as seen below class-map match-any url-block-class match protocol http host "*youtube*" ! policy-map block-class policy-map ...
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0answers
46 views

What is the difference between Custom Queuing and Weighted Fair Queuing?

I understand that both mechanisms send traffic in a round-robin fashion, and the traffic is sent proportionally to their weight based on the ToS of the traffic. However, I don't understand the ...
2
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1answer
456 views

Cisco QoS trust and cos-dscp dscp-cos Mapping behaviors

Regarding our current Cisco QoS implementation, to get a deeper understanding I would have some questions I read this: https://www.cisco.com/c/en/us/support/docs/wireless-mobility/voice-over-wireless-...
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1answer
228 views

QoS color aware and color blindness?

QoS - Color Aware and Color Blind mode. Is color - red, yellow and green is a kind of analogy for violate, exceed and conform traffic rate. If so, whey did they come for the colors here. I mean ...
3
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2answers
459 views

QoS for OSPF, VOICE and CRITICAL Traffic

I plan to implement the QoS policy below. The target is to garantee bandwidth to VOICE and CRITICAL traffic. It should be 1/3 for Voice and Video, 1/3 for Business Critical traffic, 1/3 for all the ...
5
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1answer
117 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 ...
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2answers
55 views

traffic shaping

I need some clarifying on that issue (little bit rusty on that) Assuming I have some limitation on the BW of 1Mb. What will happen then there is incoming traffic of 1.5Mb for 10 sec - some of the ...
0
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1answer
76 views

How color is encoded in the DS field/ToS IPv4 - QoS?

The RFC 2698 says - "The color is coded in the DS field [RFC2474] of the packet in a PHB specific manner". I am trying to understand how color is encoded like in the IPv4 header - in the TOS field ...
3
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2answers
428 views

QoS: priority-queue out

I'm trying to understand the priority-queue out command configured on an interface. Based on what I have read, here is what it does : the Priority Queue (Queue 1) on the switch will be emptied before ...
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1answer
43 views

I limit the port INGRESS but get packet loss

I use the limit speed method to limit the Juniper Switch port EGRESS and INGRESS speed. but after I added the INGRESS filter to my port, there will loss packets on the switch every port. anybody ...
2
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1answer
422 views

QOS police vs bandwidth - is this configuration wrong?

I understand bandwidth in QOS is use to guarantee a minimum bandwidth I understand police in QOS is to set a limit to the maximum bandwidth. class test_out police **1608000** 50000 100000 conform-...
3
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2answers
264 views

Hierarchical QoS

As I understood, the main difference between H-QoS and QoS is the level of category granularity, in which we could apply different QoS tools and policies. For example in simple QoS, just ...
1
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1answer
146 views

DSCP re-marking on Cisco Switch

I've followed the commands in this post: DSCP trust boundary policy-map MARKDOWN class class-default set dscp ef Interface Config: interface gig 0/1 service-policy input MARKDOWN The ...
3
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1answer
109 views

Is Cisco SG300-10PP & QoS appropriate to share bandwidth?

We're going to let some empty space in our office building soon. The potential client needs an internet connection for their systems (including VoIP).For ourselves we have a resilient ethernet setup, ...
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1answer
58 views

Latency in Network [closed]

My company uses trading application where latency is utmost important. I have few ideas but really dont know how to implement. Like I want to know 1) How can I Prioritize applications by 802.1q tag. ...
1
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1answer
726 views

Cisco 3850 Output Drops IOS XE Everest Version 16.6.1

We have a MPLS link connected to our 3850 with voice traffic, our interface have 1Gbps and the link is limited to 200Mbps. Our interface shows output drops, and the client device shows overruns. What ...
2
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1answer
1k views

Quality of Service: Questions about input and output service policies prioritizing the same traffic

This question/lab was created with Cisco networking hardware. I have asked this question else where with no responses. I am new to QoS, but I have spent the last few days researching and I've ...
2
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1answer
2k views

Default QoS Behavior on Catalyst 3650/3850 Running IOS XE 16.3.6

I am trying to better understand the default queuing behavior on Catalyst 3650/3860 running IOS XE 16.3.6 Denali. Is QoS enabled globally by default? Coming from working with Catalyst 2960X on IOS 15 ...
2
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1answer
62 views

HP 6120X Blade switch QoS

I just got access of blade center and i was looking at configuration of switch which is following. I can see switch has already QoS configured, I am not very expert in QoS so trying to understand ...
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0answers
60 views

traffic of AF41 marking under interface

I have used port-queue commands most of the time to check traffic status under BE, EF, AF4. But I haven't found command to check for AF41 to AF42 on Huawei VRP or cisco IOS. How can check traffic of ...
2
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0answers
55 views

Service Policy CISCO 7606 not work [closed]

I have bandwidth control in cisco 7606 but the same is not limiting my clients. I checked the settings and did not identify an error. This box is 1 replacement for 1 old 7606 model. Is it necessary to ...