Questions tagged [performance]
For questions about network performance, where factors like Bandwidth, Throughput, Latency, Jitter and Error rate are all often considered important.
52
questions
1
vote
0
answers
57
views
802.11ah Wi-Fi HaLow theoretical network throughput with 100s of clients
What is the theoretical network throughput of a 802.11ah WiFi HaLow network with lets say 300 clients connected to a single AP? The networking overhead is supposed to grow with the number of stations ...
- 121
0
votes
2
answers
2k
views
100Mbit vs 1Gb/sec transferring 10MB file...speed difference?
Two PC's A and B speed of transfer bits across the wire...
100/Mbit Link (100,000,000 bits)
1Gb/s Link (1,000,000,000 bits)
File Size: 10MB (80,000,000 bits)
I'm trying to figure out if we have ...
- 29
0
votes
1
answer
81
views
"Expected" packet loss under heavy network load in TCP cubic
context
We have two machines that receive a lot of data, and mirror each other's content with rsync. When monitoring these boxes via ICMP echo requests (using the mtr tool), we see up to a couple % of ...
- 3
0
votes
1
answer
101
views
What is the difference between server-side and client-side data transfer rates in a speed test?
I am using CNLab's UX desktop app to test my internet connection's consistency as shown below for the upload. What is the difference between server-side and client-side data transfer rates. For VOIP/...
- 103
0
votes
0
answers
170
views
TRex Warning : number of rx packets exceeds 101% of tx packets!
+------------+
| |
+------------| tester |<-------------+
| | | |
| ...
1
vote
1
answer
2k
views
Is it possible to conduct a bandwidth test using iperf between two computers located on different network? [closed]
Is it possible to check bandwidth using iperf between two computers on different networks (i.e., geographically apart)? I researched a lot, and every answer on Stack Exchange or any other website ...
user73506
0
votes
1
answer
736
views
Does propagation delay of a packet sent across a link depend on the link transmission rate? [duplicate]
I was doing the exercises at the end of chapter 1 of Computer Networking: A Top-down Approach by Jim Kurose and came across the following problem;
How long does it take a packet of length 1,000 bytes ...
- 103
1
vote
2
answers
143
views
Intermittent Network Performance Problems
I've been dealing with an intermittent issue in my network for several weeks now.
Symptoms:
Periodic "Destination host unreachable.", and similar errors when pinging. The following is ...
0
votes
3
answers
712
views
Routing in layer 3 switch vs old modem/router?
I believe what I am about to ask is on-topic.
I have Cisco DPC3828S (wireless router/modem) from ISP, which I cannot turn into bridge. So, it does routing.
I have layer 3 switch, Cisco SG350-10.
...
0
votes
1
answer
153
views
Is performance worse routing between two vlans on one interface than routing between two NICs with no vlans?
I have a Linux router with one interface that is connected to a switch in port 2.
Port 2 on the switch is a member of vlan2(ISP) and vlan3 (office devices).
My router is currently routing between ...
- 125
5
votes
1
answer
6k
views
How do CPU and RAM affect a router's performance?
I've seen a lot of circumstances when there are 50-100 users in the net cafes -- under normal gaming and web browsing activities with no heavy downloads -- causes the router to drop packets (leads to ...
- 423
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
4
answers
206
views
How can we troubleshoot Wifi problems apart from the basic tips?
We have a Zyxel Wifi with an NXC2500 and two WAC6503D-S access points in our office. Around 30 devices are connected. We have both a 2,4GHz and a 5GHz radio active, both on channels without known ...
- 101
0
votes
1
answer
326
views
Measurable performance impact of port mirroring on a firewall\security device?
I am setting up a network monitoring device which recommends that I create a mirror interface on my firewall/security appliance and send all packets to the monitor for sniffing, logging, and ...
- 101
0
votes
1
answer
4k
views
How to Troubleshoot Network Latency Step by Step
Does anyone have an idea of how to troubleshoot high network latency step by step?
For example, let's say we have a remote office. And all users are from that office are having high latency accessing ...
2
votes
1
answer
90
views
Random intercontinental TCP streams are slow
I have a home server in New Zealand and a remote server in Amsterdam of the following configuration:
I have a simple test script:
#!/bin/bash
for i in `seq 1 20`;
do
scp root@remoteserver:~/...
- 121
9
votes
3
answers
8k
views
Is there a performance difference between a managed an unmanaged network switch?
Is there a tangible difference in speed/latency between a managed and unmanaged network switch?
- 93
2
votes
1
answer
237
views
Definition of bandwidth capacity for an internet connection
First, I want to test the data rate of a fibre-optic internet connection, but I understand that results are affected by the circumstances of the test, like number of hops between the CPE and the other ...
- 123
2
votes
1
answer
2k
views
Is this a normal TCP retransmission pattern?
Our organisation's desktop computers have been performing not satisfactorily during their accessing of network resources. Out of suspicion, I perform a TCP retransmission statistics. Below picture is ...
- 123
1
vote
1
answer
120
views
Can bad cabling affect the overall network?
TLDR: Can a handful of problematic lines negatively impact the performance of the network as a whole? ... or would any problems stop once it reaches the switch?
Longer Version (background):
A ...
- 113
3
votes
1
answer
6k
views
TCP DUP ACKs occurring on a seemingly regular basis
I noticed this while checking the performance of our Teamviewer connections. If i start a download test, the following pattern can be observed in the TCP stream graph provided by Wireshark:
The red ...
- 33
1
vote
1
answer
4k
views
How can I calculate the network throughput using ping responses?
I have the tcpdump data for the below mentioned command.This is to perform a test on the network to derive the bits per second.
Is it possible?
sudo ping6 fd9c:b4f9:3108:1045:213:5003:59:324e -c 10 -...
- 1,412
6
votes
2
answers
556
views
how to find the right value of MTU Jumbo frame
we take the decision to set jumbo frame on all our linux machines
we have hadoop cluster with master machines , workers machines and kafka machines
our switches ( Cisco ) are suitable to Jumbo frame ...
- 61
1
vote
0
answers
215
views
PPPoE Performance Test [closed]
I'm looking for some tool or a way to execute performance test with pppoe account.
simulate PPPoE sessions and traffic.
Example:
I have a PowerEdge R420 running a VYOS, I was wondering, how is the ...
5
votes
2
answers
2k
views
Cisco ISR 4000 Performance Levels, router shaper
I am trying to understand Cisco ISR 4000 Performance Levels.
In the document ISR 4000, one can read the following paragraph:
It's actually quite simple. The router shaper applies only to traffic
...
- 399
2
votes
1
answer
181
views
ACL on Nexus 3064PQ performance
We are using this switch as L3 and planning to run some ACL to stop bad traffic. I never run ACL on switches so wondering is there any performance impact or how bad it will be? if anyone has any ...
- 4,371
1
vote
2
answers
2k
views
Cisco performance issues C890 series
I'm working on a complex project that includes Linux and Cisco routers. I am fairly new to networking and i'm using cisco command lines for the first time, so please be nice and don't hesitate to ...
- 13
2
votes
3
answers
4k
views
Why such a large discrepancy between theoretical and real Wifi speeds?
I am testing the actual speed of transferring a file from a network share.
Over my 1 Gigabit Ethernet I get about 120 MB/s - that's 96% of the theoretical maximum.
Over my old Wireless G I get about ...
- 123
2
votes
2
answers
137
views
How to design a wireless network for efficient multicast or broadcast communications?
First, a little bit of background information: I'm working on some custom software that allows a group of computers on the same LAN to co-operate on a real-time task in a distributed, fault-tolerant ...
- 141
2
votes
8
answers
335
views
What are the concerns other than latency for network tuning?
Everywhere I keep finding "to achieve low latency" or "latency is of concern", do this!
So, I don't really get what are the other concerns other than latency. I mean who doesn't want low latency? Or ...
- 165
1
vote
1
answer
65
views
How to make a web application run as fast as when I run it directly through the server? [closed]
I have a web application that run from a local server. When I run the application from the server using remote desktop connection, the application performance is smooth and fast. For example, ...
- 11
3
votes
3
answers
210
views
Cisco Aironet performance took a big hit with VLAN
I manage a wireless network of 50 Aironet 1130AG access points spread across 8 Catalyst switches. This ran very smoothly until I had to employ VLAN tagging. There is now the passwordless Default (1) ...
- 131
1
vote
1
answer
260
views
Cisco ACL performance question?
We have ASR1006 Router and we are running ACL on it to allow specific
port to specific server.
Question is there any ACL performance impact on individual IP vs full
subnet. like following example.
...
- 4,371
4
votes
1
answer
2k
views
IPv4 vs IPv6 performance
What are the differences in performance for IPv4 and IPv6? Is there much of a difference in speed? and what are some of the methods that could be used to test this?
- 137
2
votes
1
answer
60
views
What is the N½ value of a network?
In the context of HPC interconnect networks (Infiniband, OmniPath, ...), I've come across the notion of the N½ value of the network, which is supposedly some performance number. What is this number? ...
- 21
1
vote
1
answer
3k
views
General best practice for VLANs and domains
I recently took a job at a school. This is only my second position as an IT professional. My only experience with corporate networks is in a large school district at another school. They used VLANs to ...
- 11
0
votes
1
answer
6k
views
GNS3: performance tests using iperf3? [duplicate]
I'm running some performance tests on GNS3 (I know I shouldn't, but it is not until Friday that I will have the college lab available), and I'm trying to compare real BW or "speed" and ...
- 15
1
vote
1
answer
138
views
NIC speed and PCI bus speed to be synchronized?
Is there any advantage point of having a Gigabit Ethernet if the PCI bus connecting NIC to Memory is a lot slower than that say just 80 MBps?
In other words, I am trying to conclude that it makes ...
- 893
2
votes
2
answers
300
views
Effects of local switch time on network performance
Given a collection of switches all communicating together, will the local time on the switching equipment configuration have any bearing on performance, or just a common reference point when ...
- 123
4
votes
2
answers
320
views
Measuring route processing time
I want to feed a Juniper router a set of routes via BGP and measure how long it takes the router to process them, including time spent on prefix filters and RPKI origin validation.
Cisco IOS XR ...
user19357
0
votes
1
answer
81
views
Simple way to monitor network performance w/o access to network infrastructure?
I work for a large organization where the network team is in some disarray (key people left/fired, etc.). My team is responsible for the performance of various client/server applications which of ...
- 1
2
votes
2
answers
3k
views
Difference in latency between public and internal IP addresses
Should there be a difference in latency when accessing resources by their public IP address versus their private, internal IP address? And if there is, would (mis)configuration be to blame?
My ...
1
vote
0
answers
98
views
CDN performance degrading during load testing [closed]
While load testing our website through Soasta we found that the API calls were performing consistently without any degrade in performance (thanks to larger Ec2's serving them and the Elastic Load ...
- 119
4
votes
1
answer
2k
views
How well does 802.11k actually perform on large-scale networks?
As a student employee I've done some research on 802.11k and I understand that it's intended to help with devices roaming and also helping the client decide on the best (B)SSID to join. In practice ...
- 348
3
votes
1
answer
1k
views
Performance differences of logging session-init and session-close invididually compared to through apply-groups
Assumption:
Your interest lies in logging each and every session
Approach 1
You configure the session logging within each and every policy, for example:
set security policies from-zone trust to-...
- 75
6
votes
2
answers
15k
views
How to "size" a Router for a Given Uplink
I'm the tech guy for a small business. (15 office computers, ~15 staff BOYD's, ~30 guest devices.) I'm looking to replace our Asus RT-N53 with a business class router and two access points each ...
- 135
3
votes
1
answer
784
views
Firewall Benchmark- Concurrent connection metrics
I intend to perform a Firewall Benchmark. I have reviewed related research papers and RFCs to create a suitable methodology. I have also examined open-source tools useful for the project (iperf, ...
- 31
5
votes
1
answer
1k
views
ACL on entry of Core Switch - Performance doubt
We are an ISP and I would like to implement ACL to protect our core network (Infrastructure) and implement some filtering on public subnet inside.
As border device we have a cisco WS-C4500X-32 4500x ...
- 2,008
3
votes
1
answer
4k
views
standard results for gigabit ethernet iperf
I can't achieve good transfer rate through scp and I wonder if the network configuration isn't tuned up correctly. I've noticed some differences when running iperf through tcp vs udp.
Are these ...
- 133
9
votes
2
answers
522
views
How to handle performance degradation deep in your provider's network?
What are some possible ways to detect packet loss deep in a provider's network that is several hops away? With multiple providers peered over BGP on our Internet edge routers, I need to be able to ...
- 7,094