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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291 views

QoS implementation for VoIP network

We are in VoIP business and running RTP/SIP traffic 80% in our network we have other servers also like www and monitoring and operation, our network is very flat and simple also we have very basic ...
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2answers
212 views

How ISP track the individual subscriber data download and falling back to lower mbps?

I work on software development for routers. So, I am aware of QoS in routers, where we can do scheduling and policing of the traffic. However, one question is still in my mind, is how does the ISP ...
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1answer
156 views

PTP traffic over 100Mbps switch with high volume traffic

Wondering if anyone has ran PTP traffic along side high volume UDP traffic on the same switch running at 100 Mbps. Would it be expected to get massive (15 us) jitter on the PTP packets without setting ...
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2answers
312 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 ...
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3answers
6k 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, ...
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2answers
2k 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 ...
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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 ...
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1answer
59 views

What kind of QoS do I need? [closed]

I have a small office. There are ~5 PCs connected via cable. There is 1 PC via WiFi, 3 VoIP phones and a bunch of cellphones connected via WiFi. There is a Gigalan switch and a internet connection ...
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0answers
43 views

Low quality of realtime audio/video calls. Route such traffic through a separate WAN connection? [closed]

We have problems with the quality of audio/video calls in our office. We get much better quality using mobile LTE connection than our fiber link. LTE connection always goes HD, but the fiber ...
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3answers
98 views

Traffic Classification

How does the switch or router differentiate between voice and data traffic? What are the parameters used in the different layers to classify this traffic?
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1answer
240 views

Cisco IOS XR policy statistics:

My goal is to see if the interface gets more than 2gbps of traffic, just to see if it's true. So I created a policy map with ACL that matches all, and all actions - violate, conform are set to ...
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3answers
280 views

What transmission service gurantees does Ethernet give?

Higher layer transmission protocols have certain properties. For example, TCP "guarantees" duplicate-free, error-free in-order delivery of packets. UDP does basically provide the same properties as IP,...
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2answers
524 views

QoS on Cisco Router to limit link utilisation

I´ve the following setup: ISP-ROUTER+-------+ My-ROUTER +-------+ ... The available bandwidth between ISP-Router and MY-ROUTER is 50Mbps. The Physical link is 1000Mpbs. All above 50Mbps result in ...
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0answers
96 views

NDE for QoS Flows on SUP720-3C?

I've setup per user Layer 2 policing on a pair of Cat6k with SUP720-3C to rate-limit wireless guest users. This is working fine and the flow table is populated as expected (with L2 QoS flows). Now my ...
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2answers
946 views

Ethernet Flow Control vs Quality of Service

What are the trade-offs/major differences of Ethernet Flow Control vs Quality of Service? How to know when to choose one over the other? They seem to both be a solution for congestion. The obvious ...
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1answer
578 views

Egress traffic shaping vs. normal output interface queue

When traffic needs to egress from an interface, it is put to an output queue. When a traffic shaper is shaping egress traffic going out of an interface, it puts the traffic in an output queue also. ...
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2answers
3k views

Why traffic shape/police ingress traffic?

Pardon me for my ignorance. I have not tried QoS nor traffic shaping/policing before. I have been pondering on whether can/why would we want to shape/police ingress traffic if you have no control ...
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1answer
830 views

How to test QoS function in router

Assumer I have a new router device of Cisco with 2 ports ethernet 10/100/1000. As everybody know that QoS based on DSCP field in IPv4 header to have difference policy for difference class. I start ...
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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 ...
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1answer
536 views

TC & Qdisc Rules with 'Leaf' classes [closed]

I'm trying to determine a class which would be used as default for new IP's on my network, here's my current setup: # Delete qdisc rule tc qdisc del dev br-lan root # Add qdisc rule tc qdisc add dev ...
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1answer
964 views

Bandwidth regulation without QoS and VLAN [closed]

Does anyone know any possibility to do Bandwidth reservation or something equal to it. Mainly to give VoIP and IPTV Bandwidth before the Internet when there is no possibility to use QoS and VLAN. It ...
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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 ...
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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 ...
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2answers
93 views

What exactly happens in the queues when a congested network applies back pressure ? [closed]

During Congestion in a network switch HW ,for examplewhen a shaping rate to the interface that imposes a speed limit lower than the maximum interface line speed . The concept of back pressure is ...
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1answer
778 views

Jumbo frame on Nexus 5k

I would like to enable the jumbo frame support on my N5k for specific SCSI trafic. I've read we can't do it per interface but only on the system itself : policy-map type network-qos JUMBO_MTU ...
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2answers
406 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 ...
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0answers
179 views

3com 5500G migration to force10 s4810

I am doing this migration with these 3com switches.So our client told me that the configuration was made for a network administrator who was fired some years ago. So I dont have any kind of ...
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2answers
632 views

ASA's traffic policy(QoS) for ipsec VPN tunnels

i have ipsec l2l VPN over internet, I wander if there is default policy in ASA for making ipsec traffic with higher priority? My question basically is, if one of packet from two packets must be ...
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1answer
282 views

The meaning of end-to-end QoS in network

When saying (end-to-end QoS) in network, what do we really mean by that?
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1answer
1k 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.
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1answer
708 views

Best method for rate limiting ingress & egress traffic hosts in colocation

What is the best method for the limiting speed of internet access for hosts in our colocation. We have a full rack which will be connected to the internet at 200/200 Mbps. We have our colo equipment ...
2
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1answer
875 views

Use bandwidth and shape concurrent

I have a question about QoS with multiple classes. In our switch with IOS-XE we use five classes to define QoS. Class 1 is a priority class so configured “priority level 1”. The remaining bandwidth of ...
2
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1answer
216 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-...
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1answer
42 views

LSA Weighted Fair Queuing Algorithm

In weighted round robin (weighted fair queuing) scheduling, suppose I have 3 queues (weights):- A (4), B (3) and C (2). I have packets of equal lengths on the 3 queues. Now will the packet output ...
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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 ...
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1answer
1k views

TXOP and Service Period in 802.11e

I want to know what is TXOP and what is service period in 802.11n or 802.11e. Is there any relation or difference between TXOP and SP Thanks, Devaa
4
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2answers
960 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 ...
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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 ...
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1answer
1k views

QoS (802.1p) for iSCSI Traffic on Cisco Nexus 3048

We're building a new core for our University and one thing that bugs me is the iSCSI network. We already considered Jumbo Frames and Flow Control on the iSCSI ports, but one thing remains for debate, ...
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1answer
973 views

How to use a layer 3 switch for QOS between gateway and hosts?

In the following scenario, is it possible to prioritize VOIP/RTP from x.x.x.51 through the gateway with a Cisco switch, and how? I need to prevent x.x.x.50 from saturating the WAN connection. ...
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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 ...
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1answer
932 views

Problem configuring QoS with FlowVisor and OpenVswitch

I am running a small experiment to isolate bandwidth with flowvisor (version 1.4, version 1.0 of openflow) implementing a port based slicing. With mininet, I create a topology that consists of a host ...
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2answers
464 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 ...
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2answers
236 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 ...
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1answer
489 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 ...
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2answers
182 views

Testing Bandwidth in preparation of tele conferencing

I am working for a company that is installing a video conferencing e-learning web application that is using a red5 media server. The client is complaining that the performance is choppy/slow, and my ...
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0answers
1k views

Configuring QoS on Cisco ASA 5525-X

I'm trying to configure QoS on a Cisco 5525-X ASA and feel like I'm beginning to get a handle on it but the queue-limit and tx-ring-limit calculations are losing me. What I've got right now is a ...
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2answers
2k 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 ...
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1answer
254 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 ...
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1answer
159 views

Throttling Internet speed to device or vlan

I have a Netgear FVS318N Firewall/Router, GS752TP Switch, and a Netgear WNAP210 AP. After a bit of searching, I have identified a machine that is using the lion's share of bandwidth (youtube). Is it ...