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

learn more… | top users | synonyms

-1
votes
1answer
1k views

what is the latency for an 8K transfer of Fibre Channel? (NFS vs FC) [closed]

I've heard it said that a 512byte data transfer over fibre channel is 10us so would an 8k (16x the data) take 160us? or is much of that 10us one time transmit overhead? I'm interested in comparing ...
3
votes
1answer
260 views

different ACK behaviors (slowing down throughput?)

I'm running netio (http://freshmeat.net/projects/netio/) on one machine (opensolaris) and contacting two different Linux machines (both on 2.6.18-128.el5 ), machine A and machine B. Machine A has a ...
1
vote
1answer
61 views

Measuring latency to a firewalled server

The firewall in front of this server is blocking ping requests. Is is still possible to measure latency to this system? If so, how?
2
votes
5answers
216 views

Measuring Site to Site Latency for Video Conferencing

We are currently looking at doing some international video conferencing, and before we go ahead and buy a system we need to measure Site to Site Latency & bandwidth objectively. I can't see any ...
0
votes
1answer
332 views

Slow upload to Server 2008 DC, Downloads work as expected

I have a Windows Server 2008 Domain Controller that I run as a do-it-all server. It has a GbE connection to the network and to every machine on the network. Downloads from the server file shares work ...
3
votes
2answers
10k views

What is best tool to measure network latency?

How do you measure network latency in Windows ? I know ping as one of the tool. Can Windows Performance monitor do it ? Any ideas which counters should I add to measure it. This is for SharePoint ...
4
votes
1answer
2k views

low latency TCP settings on windows 2008 R2

I am running a third party software on a W2008 server. This client connects to a server via TCP. The average ping times between the two are 1ms. However, when I check the tcp connection in resource ...
0
votes
1answer
190 views

Linksys SRW248g4p Latency Issues

Pinging between the linksys the ping times are averaging 40ms. I have evening tried pinging between two Linksys switches that are connected to each other directly using the GB ports. There have no ...
2
votes
3answers
137 views

How to determine the fastest location for a server?

I'm in Australia and I'm looking at US hosting options because the prices here are embarrassingly extortionate. Are there any good, free online tools I can use to find out which location in the US has ...
2
votes
3answers
1k views

How much does a IPtables router slow down a connection?

I would like to know if introducing a new gateway in my network will slow things down. The question may sound unclear but here is an illustration: Before Installing gateway server Main Router ...
0
votes
4answers
3k views

Accurate way to check latency between Server?

First of all, I hope my post are is posted in the right section . Below are something i got confused hope you one can help. My business partner 's IP server are in: Sanjose, CA , and I am looking for ...
0
votes
1answer
532 views

What’s the best switch with bandwidth limiter for my Internet Cafe?

I'm looking for the best switch and router for my internet cafe, that have bandwith limiter and have low latency... Thanks
5
votes
7answers
7k views

Latency in TCP/IP-over-Ethernet networks

What resources (books, Web pages etc) would you recommend that: explain the causes of latency in TCP/IP-over-Ethernet networks; mention tools for looking out for things that cause latency (e.g. ...
2
votes
2answers
350 views

DNS Resolver Speed Techniques

I recently received a reply to my concerns about some DNS servers being slower than others despite all servers being anycast: In practice, most resolvers won't be impacted by the slower paths to ...
2
votes
1answer
958 views

how can i reduce the lag in my sshd session?

I'm trying to use various ncurses programs through ssh but there's lag up/down in the sshd. I'm wondering if there are any tips like sshd config settings or tcp/ip settings that can help reduce the ...
5
votes
3answers
3k views

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 ...
1
vote
1answer
79 views

VPN traffic is quicker than across the internet with open ports

I have a site to site VPN link and ports open on its public IP for a service. I can connect up to the remote server using the private Ip address of the remote subnet across the VPN and it takes about ...
0
votes
1answer
83 views

Latency of Harddisk-Access WLAN vs USB (Windows)

it would be kind if someone who is an expert on this field state what I have to expect in regards to the latency accessing files for the given scenarios (comparing them): A) Current Windows PC with ...
1
vote
2answers
159 views

Is latency the time it takes to get the first byte?

If I request an image from a server, would latency be the time it takes to receive the first byte of the image?
0
votes
4answers
3k views

Remote desktop over 500ms latency: What is the best client to use?

We have a very slow RDP session from NYC to India (500ms) and we are looking for a client that will withstand this latency. What do you recommend in this circumstance? Is there a better remote ...
1
vote
1answer
772 views

Which hosts have low latency across United States and Europe?

I'm looking for some information on web hosts that have low latency (<100ms) to both the United States and Europe. The host can be in either the United States or Europe. Latency is most important ...
0
votes
4answers
4k views

How can I troubleshoot excessive latency between client and server?

On a large private network there seems to be excessive latency between two boxes which I control. This is stopping the server providing a web service to the client as its causing timeouts. Here's a ...
0
votes
1answer
208 views

What is the best way to detect how/where server latency occurs?

I'm managing a small social media site, and its been for the past few days experiencing intermittent server lags. The site will choke loading a page, and moments later, the same page will have no ...
3
votes
3answers
673 views

Small TCP Window on WAN between 2 Locations

Site A: Denver datacenter. 60MBPS. Site B: Chicago. 100MBPS. ICMP pings: Packets: Sent = 176, Received = 176, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 74ms, ...
2
votes
2answers
427 views

Traceroute provides a route that takes longer than 100 hops

I have a server that I configured using zoneedit. Upon running "traceroute" on it I notice that it takes more than 100 hops. How do I lower the number of hops? Is this really that bad or am I too ...
0
votes
3answers
456 views

howto measure network bandwidth/perf

we have a corporate LAN of approx 200 nodes behind a firewall and recently upgraded bandwidth of ISP. Now we want to measure the performance / bandwidth (internet as well file copy perf on local ...
3
votes
2answers
455 views

Another benefit of Lighttpd in front of Apache

I have read in a site that another benefit of having Lighttpd in front of Apache is lower number of child processes. Lighttpd will handle keep-alive and client requests while child processes of Apache ...
2
votes
3answers
568 views

TCP handshake latency

I have 2 machines on a 100 Gb/s LAN which talk to each other over TCP. When I do a tracert or a ping from the client to the server, even a large ping, I get an answer in less then 1 ms. However, when ...
6
votes
6answers
3k views

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 ...
8
votes
2answers
5k views

Internet latency map

I would like to see a latency map, showing the lowest latencies achieved between various destinations around the world. What is for example the lowest latencies achieved between Denmark and India. ...
2
votes
2answers
197 views

How remote warfare works when even my satellite TV and remote server has latency? [closed]

This question is after reading this article. My title asks it all. How the connection for this remote warfare works with a absolutely low network latency (which i believe is essential to achieve a ...
0
votes
2answers
2k views

Network latency — how long does it take for a packet to travel halfway around the world? [duplicate]

Possible Duplicates: How does geography affect network latency? How much network latency is “typical” for east - west coast USA? If I'm hosting an app in NY, what kind of ...
70
votes
8answers
50k views

How much network latency is “typical” for east - west coast USA?

At the moment we're trying to decide whether to move our datacenter from the west coast to the east coast. However, I am seeing some disturbing latency numbers from my west coast location to the east ...
0
votes
2answers
23 views

Why same HTTP operation's connections number difference under the same surrouding?

Under the same pc to operation one HTTP operation. Lan operation has less connections number than wan's (or add network latency). Why is it so like as I said? What determines how many connections ...
1
vote
2answers
2k views

use of tcp_delack_min on redhat linux (kernel 2.6.18)

we're moving from Solaris to Redhat Linux, and trying to duplicate our low-latency setup, that, on solaris, includes the ndd settings related to TCP NO DELAY, and NAGLE ALGORITHM. I got the impression ...
0
votes
1answer
639 views

fast way to find network user computer on domain hogging all wan bandwidth

i have a network of about 40 domain users and i have huge latency wan issues, like 1400ms for google.com pings. I have noticed that the problem goes away after everyone goes home for the day. I would ...
2
votes
3answers
3k views

Terminal server performance over high latency links

Our datacenter and head office is currently in Brisbane, Australia, and we have a branch office in the UK. We have a private WAN with a 768k link to our UK office and the latency is at about 350ms. ...
0
votes
1answer
562 views

IRP_MJ_WRITE latency up to 15 seconds

We have written an application that performs small (22kB) writes to multiple files at once (one thread performing asynchronous queued writes to multiple locations on behalf of other threads) on the ...
0
votes
1answer
90 views

Benchmark of provisionning delays of various cloud providers

Cloud computing supposedly lets you instantiate on-demand processing power through additional VMs. The allocation process is frequently advertised as fast without further details. My personal ...
3
votes
1answer
381 views

Can Linux RAID 1 account for high latency?

Scenario: we're running a large (3TB total in cluster) Solr installation in EC2. I'm only concerned about disk performance on the read side of things. We suspect that we are limited by disk I/O and ...
0
votes
4answers
177 views

Is asymmetric latency common in practice?

This is a follow-on to a question posted on stack overflow about whether it is possible to determine the one-way latency of a point to point connection without using externally synchronized clocks - ...
0
votes
6answers
2k views

Why am I getting long TCP connect latency on connect in a LAN (over a cross!)?

I am measuring a time of about 100-150 milliseconds from sending TCP SYN to getting SYN/ACK, between two linux computers connected to the same Cisco switch. Consider: The machines are very powerful, ...
1
vote
1answer
2k views

Can't stream media on network

Long story short, at our office network, we can't really certain things. Last.fm downloads an entire song before playing it, and YouTube loads and then all of a sudden the entire video is loaded and ...
2
votes
2answers
3k views

Should I be concerned about my iSCSI SAN traffic?

I have a meeting with DELL today to discuss some of our SAN setup and I want to be able to talk about what I am seeing. We have an average Latency of 20ms. I'm attaching a screenshot of what it is ...
2
votes
3answers
956 views

Route traffic to node with lowest latency in HAproxy

Is it possible to route requests via HAproxy to a server that has the lowest latency from the source IP? This seems like a much needed requirement but I can't seem to find anything. My problem is ...
2
votes
2answers
404 views

How much overhead does the Chinese firewall add to a network conversation?

Does anyone have any stats on this? I'm mainly asking from a private network perspective (assuming that they are affected by the firewall as well). That is, all of my apps that are in use in China ...
1
vote
6answers
4k views

MySQL performance over a (local) network much slower than I would expect

MySQL queries in my production environment are taking much longer than I would expect them too. The site in question is a fairly large Drupal site, with many modules installed. The webserver (Nginx) ...
32
votes
7answers
66k views

Why is the response on localhost so slow?

I am working on a tiny little PHP project for a friend of mine, and I have a WAMP environment setup for local development. I remember the days when the response from my local Apache 2.2 was immediate. ...
7
votes
3answers
1k views

Does routing distance affect performance significantly?

When I say routing distance, I mean on a global scale. For instance, if my target audience is in China, do I look for a host within China?
10
votes
6answers
14k views

How does geography affect network latency?

I have the option of hosting our database/web server at a managed hosting company on the East Coast (US) or one on the West Coast (US). Our company is based out of New York City, and both hosting ...