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
0answers
26 views

How to determine root-cause of network latency and disconnections [closed]

I am connected to internet through ADSL. It happens frequently that i see very sharp latency in internet speed and even sometimes i am not able to browse. When calling the ISP they confirm they do not ...
0
votes
1answer
44 views

Response time of TCP congestion control

I would like to know about the overall latency of the TCP congestion control for adapting to varying network conditions. Specifically, my questions are: How fast can the system react after a change ...
0
votes
2answers
46 views

Delay, Packet length and transmission rate

Why does the delay in sending a packet from source to destination doesn't depend upon the transmission rate and the packet length? If we look at the delay formula then it is, L/R + D/V.
13
votes
6answers
3k views

Network latencies between opposite ends of the Earth

This is just out of curiosity. I'm currently in South-east asia, and when I pinged domains such as bbc.co.uk and google.com (in California), I get latencies of around 5ms as below: 64 bytes from 151....
0
votes
1answer
29 views

Can clock synchronization ever be more than guesswork within a certain interval?

Assuming consistent spacial interference, e.g. The time for packet Z to get from point A to point B will always be constant. The time for packet Z to get from point B to point A will always be ...
0
votes
1answer
46 views

Estimating bandwidth requirements and productivity gain from traffic data

My small office has a 30Mbit/s internet connection, on which two or three people work. We could get twice the bandwidth at a substantial cost. I imagine a bandwidth upgrade would slightly improve ...
0
votes
1answer
68 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 ...
10
votes
2answers
2k views

Does bridging add delay?

If I use a bridge to perform traffic sniffing like man in the middle will the bridge add a delay? And what word should I use delay or latency?
1
vote
2answers
94 views

How to measure time a request takes between two machines?

I need to calculate the time it takes between: a request sent from a machine the request is received at another machine I can do it by logging, but the clocks at these 2 machines are possible have a ...
15
votes
2answers
2k views

Serialization and serialization times in 40G/10G and 100G/25G Ethernet

I've recently been involved in discussions about lowest-latency requirements for a Leaf/Spine (or CLOS) network to host an OpenStack platform. System architects are striving for the lowest possible ...
0
votes
1answer
76 views

Weird packet lost. Looking for some input

Like me start by saying I'm not an network expert but this situation got me scratching my head and you guys might be able to help. The infrastructure is 4 switches (Dell 2848). 2 For the LAN and 2 ...
3
votes
1answer
391 views

What is the relationship between throughput and latency

Looking at the structure of a TCP packet, such as discussed here: What is the internal structure of a mobile phone call packet/datagram?, this indicates that a TCP packet size is 192 bytes excluding ...
2
votes
2answers
673 views

What are the differences between TCP iRTT and ICMP Ping?

I’m attempting to estimate latency between my PC and any servers/clients it interacts with. I don’t want to use Ping for various reasons (requires both ends to allow it, would require additional ...
13
votes
4answers
10k views

What's the difference between `Latency` and `Round Trip Time`?

Golang community provide a HTTP/2 demo website to compare the performance between HTTP 1.1 and HTTP/2. We can choose different latency, e.g. 0s latency, 30 ms latency, 200ms latency. Is latency a ...
3
votes
2answers
64 views

are the RTTs additive?

By using the ping, I calculate the RTT between A and B. I calculate the RTT between A and C. I calculate the RTT between C and B. Is it possible to compare the RTT of topological link A->B with the ...
4
votes
2answers
547 views

does the DSL distance really add more latency

I've been using dsl internet for quite a while and having a ping from Algeria to France of about 90 ms , after trying to ping some locations in Algeria , i am getting about 50 ms, ping to my gateway ...
4
votes
2answers
460 views

High Jitter and Data Loss on Cisco Meraki Z1

Our office is running a Cisco Meraki Z1 Security Appliance and recently (March 5th) the internet has been dropping out intermittently. The appliance remains online but the internet either doesn't work ...
0
votes
1answer
398 views

How to measure latency and udp-jitter from the end-server [closed]

Is there anyway to monitor a latency and jitter from SLA Router to EndClient(Linux Server). I have tried to use IP SLA with UDP Jitter but it didn't work. Diagram SLA-Router -------> Linux ...
1
vote
1answer
1k views

Is RTT the same as round-trip propagation time?

As far as I know: (1) Latency (τ) = transmission delay + propagation delay + queuing delay + processing delay (2) Round-trip time (RTT) is two times the latency (assuming the same latency both ways) ...
2
votes
3answers
3k views

Why can insufficient bandwidth reduce latency?

In this article, it is stated that latency does not affect bandwidth, but insufficient bandwidth can reduce latency. Can someone explain me the latter part of the statement? How would insufficient ...
3
votes
1answer
1k views

What is the latency of IP over Infiniband compare with 10Gbps fibre network?

What is the latency of IP over Infiniband compare with 10Gbps fibre network? 10Gbps network is something like a Solarflare low latency NIC card. How well does IP over IB perform not just throughput ...
3
votes
1answer
2k views

What is the value of EstimatedRTT at first time?

Although this question might be marked as duplicated! I'm asking again because other question's answers like this couldn't help me. So please consider the case and don't mark it as duplicate and ...
2
votes
2answers
296 views

Dynamically generate OSPF/BGP routes based on Internet latency

Scenario Three Offices with 2 ISPs each - utilizing static routing to the ISP. Each office has a VPN and leased point-to-point circuits connecting the offices in a ring. A VPN is also connecting the ...
2
votes
8answers
255 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 ...
2
votes
3answers
355 views

How can I determinte the reason of server-to-server latency in my network? [closed]

We have a proplem with server-to-server latency. How can I determine the reason for it? These servers are connected to different Cisco switches. Althought the reason for this problem might not be ...
1
vote
1answer
561 views

Using the value of RTT to estimate the latency

Generally speaking, we can calculate the packet delivery time using this formula, Wikipedia: Latency = Transmission delay + Propagation delay + queuing delay + processing delay My question is: Is it ...
0
votes
1answer
325 views

Latency of AOC vs passive DAC

Long time ago I heard from friend that on really short distance using optical links makes no much sense because comparing to passive connection optical interfaces introduce another layer of hardware ...
1
vote
3answers
3k views

How to measure the firewall latency?

I want to make a lab experiment to measure the firewall (a hardware) latency. This firewall can do Deep Packet Inspection (DPI) on some industrial protocols (you can consider as TCP payload inspection)...
4
votes
2answers
11k views

How to find out TCP/UDP latency of your network?

Many people often suggest you to use ping command to find out your network latency. But it is false and a myth you often find in articles on Internet. ICMP ping was never designed to find out latency ...
0
votes
3answers
496 views

Measure latency and other statistics by comparing PCAPs

I need to measure certain statistics, such as latency, packet delay, and jitter. Would it be possible to measure these statistics between 2 nodes by sniffing traffic on both ends and then comparing ...
1
vote
2answers
150 views

Cisco VLAN configurations with WAP - Poor performance

We've recently applied a new modification to our network config. Separating two SSIDs into a guest \ corporate split config. All of the VLAN and DHCP scopes are functioning in the way it was designed ...
2
votes
2answers
4k views

What's the difference among bandwidth, ping, ping rate and latency?

All these terms are quite related but I couldn't understand when to use which. I often hear that some networks have low bandwidth and high ping rate for online gaming. I thought they might be ...
1
vote
1answer
2k views

IPTV Cisco configuration for C2960

I have attached a network diagram explaining IPTV network , i have below queries to understand & configure IPTV . All ports on edge switches are configured as access ports in VLAN 101. On Core &...
2
votes
1answer
65 views

Setting policy on a Steelhead Mobile Controller (SMC) for “Latency-based location awareness”

When setting policy on an SMC with reference to Location Awareness - > Latency-based location awareness -> Optimize over adapters specified below if latency to SteelHead is more than: <#> ms: ...
2
votes
2answers
575 views

On a Layer 3 switch, what part does the CPU play in forwarding packets?

I am a Systems Administrator at a small firm. We are latency sensitive. When forwarding packets, what protocols use the CPU and which use the ASICs? We have mostly Arista 7124's (for the most latency ...
1
vote
1answer
397 views

Website not loading/very slow only on a client's netwok [closed]

I really need some help to explain following two scenarios as I only have little network troubleshooting skills. I am supposed to go to these clients and give a valid reason for these issues. The ...
5
votes
2answers
3k views

Switch Buffer Sizing

What is the relationship between a switches buffer size and the effect it has on latency? I am aware of the bufferbloat issue and understand that buffers that are too large in networks of slower BW (i....
1
vote
2answers
129 views

Random latency on a wireless LAN

I'm facing a weird situation. Office LAN configuration is : A Netgear router as the main router An Ubuntu PC with UniFi controller software 10 UniFi APs At anytime, the latency between a computer ...
1
vote
1answer
194 views

How much influence does multicast and IPv6 have on latency?

I am looking for a fast and a diverse library for my game engine network. I have searched for a while, and I decided to use a simple one because of being fast to understand. I saw there are better ...
2
votes
1answer
152 views

Estimating latency via distance and betweenness

I want to compute the relationship between delay (latency) with distance and betweenness. More specifically, if I know (let's assume) that the distance and betweenness values for two different ...
3
votes
2answers
176 views

Transmission Rate in terms of distance

If the transmission rate of a physical link, such as ethernet cable, between a sender and receiver is set to be 100Mbps, does it imply that the receiver will receive 100Mb of data in each second? What ...
3
votes
2answers
347 views

Network latency and network bandwidth correlation

Today I was pinging random websites, and I decided to ping a website, from which I was downloading at the speed of 2mb/s, and the ping(latency) was 10 ms. My question is, if the answer from the ...
2
votes
1answer
148 views

Loosely speaking, at any given moment, how much of the internet is buffered?

When we ping a major web site, we're roughly measuring the delay between our device and the geographic location of the server that the site has chosen to send us to. It really could be anywhere. but ...
4
votes
1answer
2k views

Basic Link Aggregation scenario with high ping latency

Resume: I'm have a really basic network cenario with some new switches that I just bought. After configuring a LAG (without LACP) between them, I started to have ping losses and high latency. I also ...
1
vote
1answer
686 views

GNS3 Latency test

So I have a small topology ( 4 AS ), and I tested it on a real environment (College Lab) with Cisco routers (2000 series). The latency from one point to another was too high when I used GNS3, the ...
4
votes
1answer
251 views

Latency in P2P Circuit

I have one P2P Circuit from our HQ to a secondary office. the distance between them is approx 2kms. Earlier when the Circuit was delivered at that time we were having an RTT of 3-4ms. It is a 10Mbps ...
3
votes
2answers
822 views

POST duration over https vs ping time? [closed]

I'm trying to get a first-order evaluation of how network latency / Round Trip Time (RTT) T, as characterized by ping time, will affect the duration of consecutive sequential POST requests over an ...
0
votes
1answer
5k views

Understanding Latency and Jitter [closed]

Analyzed 2 different internet connection. Details are as: Net-1: Download Speed: 2699 kbps (337.4 KB/sec transfer rate) Upload Speed: 4737 kbps (592.1 KB/sec transfer rate) Latency: 172 ms Jitter: ...
2
votes
2answers
1k 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 ...
3
votes
1answer
1k views

When should a transparent clock or boundary clock be used when designing a network supporting clock synchronization? [closed]

When designing a network incorporating IEEE-1588 (PTP), packet-delay variation (PDV) is a significant source of timing error. Both boundary clocks (network nodes which act as a slave clock to upstream ...