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Questions tagged [latency]

Latency is the time period between a signal being sent and a signal being received

Latency is the time period between a signal being sent and a signal being received. In computer networking this can be the time between a sending of a packet and receiving of a packet.

To illustrate we can use the ping command:

PING google.be (173.194.66.94) 56(84) bytes of data.
64 bytes from google.be (173.194.66.94): icmp_req=1 ttl=47 time=76.6 ms
64 bytes from google.be (173.194.66.94): icmp_req=2 ttl=47 time=74.8 ms
64 bytes from google.be (173.194.66.94): icmp_req=3 ttl=47 time=79.6 ms

The latency here is 76.6 ms.

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iproute: disable "tc" command

I'm after running this command to simulate a network latency of 500ms with 100ms std deviation: tc qdisc add dev eth2 root netem delay 500ms 100ms Trouble is, I forget how to cancel this command! My computer currently has an awful latency and I…
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Akamai vs smaller CDN for small/medium-size ecommerce traffic? (caching, latency, NetStorage)

The small/medium sized online retail company I work for uses Akamai as our CDN for static images, but I'm wondering whether it might be hurting rather than helping and, if it's suboptimal, what we should be doing instead. We get monthly traffic of…
Aaron
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OpenVPN over TCP, terrible latency but only on Win7 x64

I know TCP encapsulated over TCP is a terrible idea in general, but I can deal with the occasional decreased performance and MTU issues, and the snowball effect TCP within TCP provides where error control kicks in on both layers. The latest OpenVPN…
mr_daemon
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Reducing Latency Between US and India/South Asia or Desktop Access on CentOS 7+ GNOME

We have a server in US DC that is getting accessed from US and India, S Asia and SE Asia. With 128GB RAM, CPU and Cent OS 7 + GNOME desktop and it runs VNC server - the server gets access through VNC viewer or Guacamole-on-vnc. We tried Nomachine…
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Linux TCP/IP tuning for low throughput network?

I have two linux machines connected by a radio modem. The bandwidth is about 2kbps, with ping times of around 400ms (5% packet loss). Currently, ssh sessions have a delay in the order of 5 seconds, although this varies. Raw telnet is similar and…
John K
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Latency on a small Linux NFS4 client/server system

We are a computer science department at a small university, running a RHEL 7 server using NFS4 and Fedora 24 clients (~40 client machines, ~150 users--rarely concurrent). We are having latency problems, and we're having trouble…
Sprenkliest
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Latency (wait ttfb) on EC2

My application is crawling a website. I use this crawler : https://github.com/rfussien/leboncoin-crawler On my dev environment, the latency is acceptable (3-4 sec) but on my prod server (ec2 T2.micro Linux/Amazon) there is a 30 seconde latency…
Julien Malige
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Trans-atlantic VOIP

We're a Canadian business on the east coast and will soon be opening up a new call centre in Australia. This new call centre will be handling our graveyard shift and will be overlapping with the current call centre. As such, I'd need to be able to…
jonathanserafini
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Hardware/topology recommendations for low latency UDP network

I'm setting up a LAN comprised of 60 end nodes that are receiving a high volume of UPD datagrams from one master server. The server sends 60 unique datagrams every 100ms, each datagram is 64 bytes. This means I'm sending 38400 bytes per second. Each…
Mattias
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Esxi with iSCSI SAN slows down with many multiple VMs running

I have a server with ESXi 5 and iSCSI attached network storage(4x1Tb Raid-Z on freenas). Those two machines are connected to each other with Gigabit ethernet, and a procurve switch in between. After a while, if I have many(4-5 or more) vms running,…
Esa Varemo
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finding the best network latency between two countries

I know there are many tools to test for bandwidth and latency, but they all rely on having at least one host from which you can run those tests. I wonder whether there's an online source or some other way to guestimate the latency or speed between…
Yoav Aner
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Intermittent high ping/latency problem

I have been working with my ISP (which is a WISP, actually Fixed Broadband Wireless) trying to figure out why I intermittently get high latency. The latency is detectable in online games and other streaming applications. If I do a trace route you…
Hugh Jeffner
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Linux machine unable to send IPv6 packets for five minutes about once per day

I am operating a router based on a Linux server running Debian stable (Buster). It uses Quagga to speak BGP4 to four peers (one of which sends the entire Internet routing table for IPv4 and IPv6, the others send significantly fewer routes). About…
ftc
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Using tc to decrease bandwidth to a specific destination address

I am trying to find the shortest path between two hosts H1 and H2 using Dijkstra code. Setting a condition in one of the switches on that path. the condition is: if the packet sending to H2 then change the path automatically. I'm using Mininet, I…
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Munin Disk Latency Alerts

I have setup my Munin server and alerts and have tested them aswell. I have set the alerts for disk usage as under: df._dev_mapper_centos_root.warning 90 df._dev_md126p2.warning 90 df._dev_md126p1.warning 90 df._dev_mapper_centos_home.warning 90 I…
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