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.
244
questions
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22
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Packet Aggregation in LTE Cat M1? [closed]
I recently came across a strange pattern regarding packet latency in LTE Cat M1 networks.
I wanted to test whether Cat M1 could also meet my latency requirements in real life since the internet ...
0
votes
1
answer
41
views
Correct interpretation "show mls qos"
I ask you to tell me in the correct interpretation of the output of commands on the Cisco Catalyst 3750.
command
"show mls qos interface fastEthernet 0/3 statistics".
Outputs the following:
...
0
votes
0
answers
14
views
In MPLS RSVP how would methods of reservations like Wildcard-Filter, Fixed-Filter method, and Shared-Explicit method be explained in simpliest terms?
More specifically I do not understand what is concedered by "transmitter described with wildcard character" in Wildcard-Filter method in RSVP? How is reservation done with this method? What ...
1
vote
2
answers
58
views
How did ATM switches that were implemented in a core of IP network improve QoS and higher data rate?
How can ATM switch improve Quality of service and data rate just by incorporating them into the core of IP network? What was used in the sore of IP networks before ATM switches and what is used today ...
0
votes
3
answers
84
views
How does policing prevent LLQ queue starvation? (QoS)
A networking course that I follow mentions the following information about LLQ (Low Latency Queuing) in QoS
LLQ designates one (or more) queues as strict priority queues. This means that if there is ...
- 759
3
votes
1
answer
501
views
Are all 64 DSCP values usable/configurable?
I have read that DSCP consists of 6 bits, thus providing us with 64 DSCP marking values (0-63).
If I understood all correctly, 21 of these values have been standardized and named (AF, EF, DF, etc)
...
- 759
1
vote
1
answer
41
views
How do multiple queues work ? (QoS)
A course I am watching mentions that an essential part of QoS is the use of multiple queues.
How exactly do these multiple queues work? Are they built into the device or is manual configuration ...
- 759
1
vote
1
answer
341
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Classification and Marking using PCP
A networking course that I am following mentions that layer 2 marking can be performed through the use of PCP in the dot1q tag.
So to help me understand, once a switch receives a frame with a dot1q ...
- 759
1
vote
2
answers
209
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Queuing and TCP Global Synchronization
About TCP global synchronization.
If we have several hosts having TCP connections with some other hosts (over the internet, for example) and our network is congested, if there was a burst of traffic, ...
- 759
1
vote
1
answer
70
views
Why does congestion happen
Imagine a network full of routers . The job of a router is to be able to receive multiple packets from multiple sources then send the packets 1 at a time in each of its outputs.If the routers are able ...
- 113
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2
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90
views
Where is priority for a particular frame set?
The Medium Access Control sublayer appends 3 bits for the priority of the frame. The possible choices for the priority are
Traffic Type
Priority
Background
0 (lowest)
Best effort
1 (default)
...
- 31
1
vote
1
answer
143
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Cisco ASR1006 QoS on pppoe session: Police percent not supported - no bandwidth for percent calculation
I want to perform QoS on specific (or all the) L2TP sessions that establish on ASR1006 router (LNS).
What I have managed already is to set a police at a specific rate for a class that matches access-...
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2
votes
3
answers
57
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QOS operation doubt
First of all, thanks for taking the time to read.
I have a doubt.
Does QOS marking in the IP header occur on every packet or does it need TCP segmentation established (TCP handshake)?
- 23
0
votes
1
answer
37
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QOS - CPU CoS Weight- pluribus switches
I have different switches and each switch has different cos-weight.
Now, it has cos3-weight, cos4-weight and cos5-weight in one switch as 15. In other it is 30.
As per this link : https://...
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0
answers
85
views
Matching QOS config from CAT 9300 to 2960XR
I am not familiar with the 2960XR syntax. I need help in matching my current QoS config that is currently on the Cisco 9300 to a cisco 2960XR. Thank you.
The QoS config is of HQoS and follows:
BRS-TC-...
- 1
1
vote
1
answer
640
views
Understand DSCP and Precedence Values in Ipv4 or Ipv6 packet
I read from this website to understand DSCP and it's corresponding IP precedence value.
For example DSCP value is '000 000' which Drop Probability is N/A(never happen) and it's Equivalent IP ...
- 358
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0
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70
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5G: Mapping QoS flow to a DRB requiring out-of-order delivery
I understand that 5GNR allows out-of-order delivery for some DRBs by configuring them as such. Also, I understand that a QoS Flow is mapped by SDAP to a DRB based on QoS parameters provided from the ...
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1
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1
answer
176
views
Are IPv4 type of service and IPv6 traffic class equivalent to each other or is traffic class IPv6 specific? [duplicate]
IPv6 has a traffic class field. According to the specification it is an IPv6 length, out of which first 6 bits are called code point or differential services code point (DSCP) and the last 2 bits are ...
- 358
1
vote
1
answer
1k
views
Layer 2 (switch) QoS in a LAN or VLAN-based QoS
In my setup above (Cisco 2960 running IOS15), I have all devices marked in red in vlan 20 (WLAN_VLAN), devices in green in VLAN 10 (PC_VLAN) and devices in yellow which are VoIP in the voice vlan. I ...
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2
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2
answers
963
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What's difference between traffic shaper and scheduler?
Can't find a clear answer in Google. Both drop packets when the queue is filled. So why two terms are used? If the shaper includes the scheduler, then what else do the shaper besides the dropping?
Or ...
- 123
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1
answer
120
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Cisco IOS How to dynamically change the queueing/shaping upload bandwidth for xDSL circuits?
In Cisco 29xx routers with IOS 15.7, we have upload queues (with the classic service-policy output command and the policy-map:
policy-map wan-shaping
class class-default
shape average 1024000
...
- 157
1
vote
2
answers
431
views
how a transport-layer protocol can provide timing guarantees?
I'm reading a textbook which says:
A transport-layer protocol can also provide timing guarantees. As with throughput
guarantees, timing guarantees can come in many shapes and forms. An example ...
- 421
1
vote
1
answer
150
views
QoS Policy to not overutilize WAN link
I have a configuration on a Cisco C897VA-K9 router that has a built in DSL modem. It has a simple internet connection via VDSL. There is a VPN configured on the device, that connects back to our main ...
- 1,700
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votes
1
answer
100
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How to compare two DSCP ? which one of DSCP 28 and 34 (decimal) has more priority?
How to compare two DSCP ? for example which one of DSCP 28 and 34 (decimal) has more priority ?
- 13
0
votes
1
answer
39
views
Traffic flow of tunnel interfaces
I would like to understand traffic flow in a router. In what direction do i need to apply a policy-map in order to affect traffic? Especially regading tunnel interfaces, as traffic both comes and goes ...
- 1,700
3
votes
2
answers
226
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 ...
- 1,700
1
vote
1
answer
1k
views
How to verify the traffic forwarding class in Junos if it is set by firewall filter?
I have a firewall filter below which puts the ICMP traffic to assured-forwarding class if the bandwidth threshold is not exceeded:
root@vmx> show configuration firewall filter example | display ...
- 1,187
0
votes
0
answers
83
views
Shaper configuration for Juniper MX480 - MPC3e 3D NG
following secario:
A MX480 with MPC3e 3D NG Linecards.
I have a new Layer2 Access provider that is providing Layer2 services between 100 and 1000MBit/s. My connection zu this services are a 10GE E-...
- 497
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0
answers
33
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can't find cbQosCMPostPolicyBitRate64 oid for cisco
i have use snmpwalk go get police Bit Rate Traffic policy-map(QOS) for my cisco ASR1006
but i need a 64bit barbecue my traffic is more of 5000Mbps
so 32bit can't handle it .
~# snmpwalk -v2c -c aaa ...
- 331
1
vote
0
answers
75
views
Upstream QoS garanteed bandwidth
In the network I'm trying to manage there is a satellite link, the upstream of which is ~ 7 Mbps. In this upstream, I need to allocate 1.5 Mbps of guaranteed bandwidth for one single host, but nothing ...
- 45
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votes
0
answers
38
views
Rate limiting xFTP traffic originating from a Cisco IOS router
We have some routers on marginal cell links that we need to pull files from using TFTP or FTP. During file transfers connections to the router become so slow as to be unusable.
Is there a way to rate-...
- 666
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0
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53
views
uncorrected snmp Qos value from cisco
hello i have a router cisco 1006
and i create a policy-map
with to class
policy-map CheckBand-BandPerUsr
class BandPerUsr
police cir 10000000000
class class-default
police cir 10000000000
...
- 331
1
vote
1
answer
80
views
QoS policy definition - Cisco guidelines vs reality
Currently designing a QoS Policy for a customer (Cat 4500 models), following the business needs, I will work on a 8-class based model definition.
Cisco has several guidelines under this perspective, ...
- 1,085
6
votes
3
answers
2k
views
How to find the client who downloads a big file?
today I found out that somebody in our organization utilized our uplink for 100%. We have Cisco WLC 2500 where I could see in application monitoring that 80% traffic of the last 90 sec was a file ...
- 93
2
votes
1
answer
1k
views
Cisco 3850: Process responsible for Softbuffers
There is a command to increase the SoftMax Buffers on 3850 switches:
qos queue-softmax-multiplier 200
This is done in percent which means i am doubling the amount of softmax buffer.
Before, the ...
- 1,700
0
votes
0
answers
566
views
QoS over IPSec Site-to-Site VPN: Concerns and Questions
(For clarification purposes: Kbps = Kilobits per second for bandwidth, KB/s = Kilobytes per second for file / data transfer stuff. I'm using them separately because XG knows KBps but not Kbps - ...
- 181
3
votes
1
answer
314
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, ...
- 133
2
votes
2
answers
440
views
What is the advantage of Supervised Machine Learning over Deep Packet Inspection in Network Traffic Classification? [closed]
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 ...
- 103
0
votes
3
answers
107
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 ...
- 141
0
votes
1
answer
576
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 ...
- 103
1
vote
0
answers
87
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-...
- 113
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votes
1
answer
2k
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 ...
- 227
1
vote
1
answer
263
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 ...
- 145
1
vote
1
answer
163
views
Packet scheduling in LTE/5G core network components
Scheduling algorithms must be used on the 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 ...
- 13
0
votes
0
answers
212
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 ...
- 145
0
votes
1
answer
102
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, ...
- 1,085
1
vote
1
answer
117
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 ...
- 551
3
votes
1
answer
474
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?...
- 551
4
votes
1
answer
722
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 ...
- 551
2
votes
1
answer
922
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 ...
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