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.

Filter by
Sorted by
Tagged with
5
votes
1answer
482 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
141 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 ...
5
votes
1answer
450 views

Traffic marking is not working properly in QoS

Traffic marking is not working properly in QoS. I have a problem with the policy map marking bit. I would like to monitor the traffic that matches the IP precedence bit 4 in Po 50, but from the ...
4
votes
6answers
687 views

Can QoS settings interfere with wireless printing? [closed]

This may seem like a rudimentary question, but I wasn't sure where else to ask it. I've set up some QoS rules on my router that give the highest priority to all traffic incoming and outgoing to my ...
4
votes
2answers
4k views

cisco 877 router QoS on traffic with a specific destination

Is it possible to throttle traffic coming or going to a specific ip address on a cisco 877 running : C870-ADVIPSERVICESK9-M, 12.4(15)T12, RELEASE SOFTWARE (fc3)? Background: we have a WAN where ...
4
votes
2answers
304 views

Cisco QoS algorithm - classification process

Question about the classification process of the Cisco QoS. I understand the concept, but I have some misunderstanding regarding the Cisco QoS algorithm. Am I true with the following reasoning: The ...
4
votes
1answer
977 views

QoS between two sites

I have a following topology where Internet service providers for both sites provide 10Mbps connection: There is a GRE tunnel between the sites and I would like to ensure that this tunnel is up even ...
4
votes
2answers
758 views

QoS for 100mb Circuit

The carrier has given me a COS profile of 102: 80/10/10 80% RT for a new 100mb circuit. I've compiled the below as my QoS policy-map and bandwidth configs. interface GigabitEthernet0/0 speed 100 ...
4
votes
2answers
2k views

How does a router/switch know which queue a packet should be put in?

In weighted fair queuing, how does the router/switch/multiplexer know which queue to put a packet into? For example does it read the headers of each packet to find out the sender and the intended ...
4
votes
1answer
144 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 ...
4
votes
1answer
609 views

Why doesn't ISPs reset DSCP at the edge before delivering traffic to customers?

Some ISPs are doing QoS based on traffic type (online streaming), such as Comcast and Cogent. Why don't they reset IP DSCP at the edge so it is not as obvious that they are doing some kind of traffic ...
4
votes
1answer
539 views

QoS Policing vs Shaping, why policing

Regarding QoS, we have two modes: shaping or policing. The policing drops packets while shaping put the packets in buffer. Shaping seems to be the better solution in a general ways, so, why use ...
4
votes
2answers
671 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 ...
4
votes
1answer
175 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 ...
4
votes
3answers
5k views

QoS or more bandwidth?

Being in SP field I sometimes hear folks say "we do not need QoS, just let's make sure we have enough bandwidth". This has always been bothering me, because currently we have a network without any QoS ...
4
votes
1answer
1k views

How do you control WAN Download Bandwith on an ASA?

I have a Cisco ASA and cannot seem to control bandwith from the Internet to the device that well. The ASA supports Shaping, but only on outbound traffic which works great. My question is how to ...
4
votes
1answer
7k views

Understand the output of “sh policy-map int” in Cisco IOS

I have a following CBWFQ configuration: ! ip access-list extended GRE-traffic-ACL permit ip host 10.10.11.2 host 10.10.11.1 ! ! class-map match-all GRE-traffic match access-group name GRE-traffic-...
4
votes
1answer
1k views

Rate limiting specific IP adresses on Cisco 2960S and 2960X series

We are looking into rate limiting some specific IP addresses down to 5mbit for various bandwidth reasons. Is is possible to rate limit ingress and egress traffic for specific IP addressees on the ...
4
votes
2answers
453 views

How to override 802.1p CoS on outgoing interfaces?

In Cisco, this can be easily achieved by: policy-map TVPrio description Set VLAN priority to 4 class class-default set cos 4 and apply this policy-map to the interface. How to do equivalent in ...
4
votes
2answers
300 views

Aggressive UDP flows

I am reading about the DBL feature on the Cisco 4500E which protect the buffers from filling up with traffic that is identified as nonadaptive or belligerent flows such as aggressive UDP flows. Since ...
4
votes
2answers
941 views

Equal WAN bandwidth for all LAN devices using Sonicwall NSA 2400/2600

I have a Sonicwall NSA 2400 (soon to replace with NSA 2600). The LAN has a widely varying number of users/devices. Some days there are 10 people onsite, some days 75-100. I want to be able to ...
4
votes
1answer
304 views

protect sensitive traffic if end-to-end QoS is not possible

I have a very typical scenario where I would like to protect IP phones traffic from high RTT, packet delay variation and packet loss on congested links. I fully understand, that QoS would help only in ...
4
votes
0answers
183 views

Shaping on ES20/7606-S

I've recently moved from point-to-point WAN to a point-to-multipoint WAN, unfortunately this has really messed up my brain...in regards to shaping. These circuits are aggregated into three physical ...
3
votes
1answer
219 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
votes
3answers
892 views

LAN QoS for VoIP

Is LAN QoS required for VoIP applications? We have basic network infrastructure: PC (Softphone) -GigEth-> [Switch] -GigEth-> [Router/Firewall] -> Internet (100 Mbps) -> [ITSP] Voice ...
3
votes
1answer
1k views

QoS on tunnel interface

My configuration policy-map Shape_FTP class FTP shape average percent 5 class class-default fair-queue policy-map Shaper class class-default shape average percent 100 service-policy ...
3
votes
1answer
215 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?...
3
votes
2answers
575 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 ...
3
votes
2answers
231 views

Applying a queuing service policy

This is on a Nexus N5624Q. I have this TA-queuing service policy : policy-map type queuing TA-queuing class type queuing queue-cos1 bandwidth percent 20 class type queuing queue-cos2 ...
3
votes
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 ...
3
votes
2answers
393 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 ...
3
votes
1answer
921 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(...
3
votes
2answers
609 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 ...
3
votes
1answer
124 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, ...
3
votes
1answer
617 views

Cisco MLS and MQC QoS - trust cos/dscp

A question about Cisco MLS and MQC QoS. I read two things on a Cisco guide: https://www.cisco.com/c/en/us/support/docs/switches/catalyst-3850-series-switches/118629-technote-qos-00.html On the ...
3
votes
1answer
992 views

QoS - Difference between MQC and HQF

I understand that the older versions of Cisco IOS implemented the MCQ and the newer one's implement HQF. Could some explain what is the difference between MQC and HQF? Thank you.
3
votes
1answer
211 views

Throttle traffic over a link?

I work for a global company in the client support department. Another department manages the network. My team is frequently asked to throttle client traffic from our on-premises Apple software update ...
3
votes
2answers
5k views

Limit bandwidth in cisco router with policy-map doesn't work

I have a problem with my scenario in limiting bandwidth of ubuntu PC in GNS3 with class-map and policy-map. this is my topology in GNS3: The R1 is a cisco 3725 router with c3725-adventerprisek9-mz....
3
votes
1answer
2k views

Configuring VLAN-based priority/QOS on Brocade NOS?

I would like to do QoS based on port-based VLAN traffic on a Brocade VDX67xx series router running NOS 4.1. Just need a way to say, "traffic on VLAN 100 has a higher priority ingress/egress than vlan ...
3
votes
1answer
3k views

How to test Wi-Fi Multimedia (WMM) QoS management with LANforge?

I would like to test the Wi-Fi Multimedia (WMM) feature of an access point AP. How can I test it using Candela Technologies LANforge-WiFIRE WiFi traffic generator? Some thoughts after reading the ...
3
votes
2answers
50 views

Understanding traffic flow on SVIs [closed]

I have a simliar question to this one: Access-Lists and VLAN and understanding traffic flow But my question is concerning service-policies. Have a look at the image above. I triet to make a traffic ...
3
votes
2answers
1k views

Extract QoS Buffer Drops via SNMP

I am in the process of rolling out solarwinds for visibility of QoS performance using netflow and CBQOS to show QoS class usage. One thing I am unsure of is what type of monitoring is available on L2 ...
3
votes
1answer
669 views

QoS DSCP AF Class Comparisons

I'm having trouble wrapping my head around DSCP AF Classes and what--all else being equal--gets dropped first. I understand packets are given a Class, 1-4. The higher the Class number, the higher ...
3
votes
2answers
130 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 ...
2
votes
1answer
213 views

Qos Packet drops

My question is : This subinterface has a Qos policy settings its speed to 800000 (800kbps) If i have an offered rate of only 19000 bps, why is there a drop rate of drop rate 3000 bps ? Service-...
2
votes
2answers
63 views

How did the sender detect the reciver speed?

Let us say we have switch with multiple gigabit interfaces and there is two machines connected to that switch, one with gigabit NIC and one with 100 mbps NIC and we start copying file from the gigabit ...
2
votes
2answers
3k views

How does throttling of network traffic work (to limit bandwidth by ISP e.g.)?

I have tried to find the answer on how network throttling works e.g. by ISP when they limit your access to say 100 Mbps. As far as I know TCP/IP itself does not have any mechanisms for that, so it is ...
2
votes
2answers
402 views

Cisco QoS Confirmation

Can anyone doublecheck my basic Cisco QoS configuration. I've got a small remote site connected via AT&T 20Mb line that communicates over an IPSec tunnel. class-map match-any QoS-Voice match ip ...
2
votes
1answer
5k views

QoS bandwith calculation

Please explain: I have two routers with QoS on them.. Both WAN-facing interfaces have a bandwidth command with the same value (100000) but the priority queue (also the other reservations) calculates ...
2
votes
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 ...