We’re rewarding the question askers & reputations are being recalculated! Read more.

Questions tagged [latency]

For questions about network latency. For instance: the propagation of your network traffic, where the transmission medium can be defect or the processing of packets by a network device has slowed down.

Filter by
Sorted by
Tagged with
0
votes
2answers
612 views

Meaning of 2 Mbps

I read this article - https://rescomp.stanford.edu/~cheshire/rants/Latency.html I have a 2 Mbps private link. This means that I can transfer at the rate of 2*10^6 bits per second ~= 250*10^3 bytes per ...
0
votes
1answer
221 views

What factors affect propagation time for wired / wifi multicast messages? [closed]

I have a newbie question on multicast delivery times. In this article on clock synchronisation they claim that the propagation time on a local network is close to zero. What is the propagation time ...
2
votes
3answers
10k views

What causes packet loss when using full bandwidth from ISP?

We have a small, local ISP that is having some networking issues and I'm trying to understand the cause to better communicate with their network guys. I work with a number of companies with different ...
1
vote
1answer
2k views

Can I somehow increase the latency / response time of a server for testing?

I am looking to make some speed performance tests. Normally our server responds within ~25 ms or so, but, I would somehow like to make it answer with delay. So basicly I would like to make some ...
4
votes
1answer
885 views

Cisco C891F-K9 ISR latency?

What is the multicast routing latency of Cisco C891F-K9 ISR? Please cite references for your answer. I think it's store-forward type and isn't one of the fastest models (given its price!). I've ...
4
votes
1answer
22k views

Initial estimated round trip time in the RTT formula

I was reading about Round Trip Time (RTT) and then I came across this formula EstimatedRTT = 0.9 * PreviousEstimatedRTT + 0.1 * Sample RTT What is the value of PreviousEstimatedRTT when it is ...
5
votes
2answers
6k views

What is the difference between data rate and latency?

Both attempt to measure the speed of a network. If data rate is the thing that is commonly measure in Mbps and latency is the thing that is measured in milliseconds, what are their similarities and ...
2
votes
1answer
193 views

Troubleshooting Slowness in Stocks Trading Applications [duplicate]

Hi Fellow Network Enthusiasts! I'm having a hard time troubleshooting a Real Time Stocks Trading Application. Here are the Steps I've done so far: Apparently, this is the only Real-Time Application ...
0
votes
1answer
154 views

bandwidth vs latency - question on stuart cheshire paper

I am trying to get my grips around bandwidth and latency. I have read Stuart Cheshire's essay, however, there are a couple of paragraphs that I cannot understand. Paraphrasing: Assume we are to ...
9
votes
4answers
2k views

Measuring per-link latency/jitter/packet-loss

I need to measure the latency, jitter and packet-loss per link in a network, as opposed to end-to-end, e.g. like this: s1-eth0 <--> s2-eth0 (~ 20µs avg. latency, standard derivation 10µs, 57 % ...
8
votes
5answers
5k views

Can you reduce RTT by increasing the bandwidth on a link?

Does increasing the bandwidth on a link from, let's say, 1mb to 30mb reduce the RTT? I have found one answer saying no. Can someone please explain? Also, what are the best mechanisms to reduce RTT?
12
votes
2answers
17k views

Is daisy chaining switches increasing latency?

This is a general question not related to specific hardware. If we have the following configuration of daisy chained switches: internet ---- core network ----- switch 1 ----- switch 2 ----- switch 3 -...
5
votes
2answers
2k views

How to reduce latency on ASA 5510 WAN link?

I have a Cisco ASA 5510 connecting our office via 2Mbit/s Internet. When Internet link fills up, latency to a well-connected host on Internet goes from 5-8 ms to 500-800 ms. With ping, it may look ...
10
votes
1answer
2k views

measure one-way latency/jitter/packet-loss

I'm getting increased latency and StDev due to route congestion and packet loss, but the forward and reverse paths go over distinct networks (e.g. one being init7.net, the other one being he.net), so, ...
4
votes
2answers
2k views

Cisco - MtR alternatives

I trying to establish if there is a function within IOS somewhere that can provide the same results of MTR , i know it can be run from Juniper devices / *Nix & Windows devices. Goal is to ...
4
votes
3answers
4k views

Network Latency issues with Cisco AP

This question involves network latency as opposed to bandwidth. I have a small remote office with a single Cisco 881W Integrated Services Router (Ethernet WAN). The WAN modem is an AdTran NetVanta ...
9
votes
4answers
3k views

High latency during downloads

I am having the same issue on my business connection 5Mbps as in another posting on this site. As soon as any computer starts a download the latency on the first hop past our DFG provided by our ISP (...
22
votes
4answers
8k views

Does physical distance affect download speed?

I just had an argument with a colleague of mine and thought I'd just reach out to the experts on this. Here's the scenario. We were using a website that measures your connection's speed. We tested ...
10
votes
2answers
552 views

Ultra-Fast Querying Using UDP Packets

I am implementing a system where one device on a network queries at a very high frequency (hundreds or thousands of queries per second) through sending a small UDP packet with 8 or so bytes of data. ...
13
votes
4answers
58k views

How to find the source of increased latency?

I've got monitoring setup on several devices in our office. The ping response time to small access switches is commonly 1-4ms... As of 3AM this morning, this has sky-rocketed to 300ms on average. ...
12
votes
5answers
2k views

Do faster segments of a network mean faster flow rate or lower latency?

This is another one of those hypothetical questions. I've been trying to figure out whether or not having a faster 'segment' of a network in between host A and host B will translate into a faster flow ...
12
votes
7answers
3k views

Accurate strategy for measuring point-to-point link performance?

I have a requirement to provide an accurate means to demonstrate line performance over a flat layer2 1Gb point-to-point Ethernet circuit, approx 100 miles apart that seemingly goes through a number of ...
3
votes
2answers
263 views

How fast can information travel through various media?

I'm working on compiling some information about network latency and designing tests to help our support folks troubleshoot problems. In order to do this, I need some basic information that I don't ...
9
votes
4answers
366 views

Recording latency between a controlled startpoint and uncontrolled endpoint

This might be a very basic troubleshooting question, but it's worth asking to make sure I'm testing things the correct way and interpreting results effectively. I have a controlled start point (a ...
6
votes
3answers
4k views

What is a reasonable latency for a L2 1G leased line between 2 sites, about 420km apart?

We need a dual gigabit connection to one of our customers and for the time being one of the lines has been brought online. The connection is between our DC and the customer's HQ, it's a L2 connection. ...
16
votes
12answers
35k views

What would cause high latency anytime there is traffic on WAN?

I have a network that has been experiencing slow internet speeds. After a great deal of troubleshooting, I have determined that any streaming content/downloads will cause the latency of WAN traffic to ...