Slashdot Mirror
Network Monitoring Appliance Looks Below 1 Microsecond
eweekhickins writes "Corvil has unveiled a new tool to help network managers cope with increasing pressure to improve performance. This appliance, from the Dublin-based company (with backing from Cisco), passively monitors traffic across networks in segments below 1 microsecond in length and correlates monitoring data with remote appliances and gives a complete picture of latency, jitter, packet loss and other phenomena that affect network and application performance. Corvil CEO Donal Byrne noted that 'If you can drop a millisecond [of latency] off, you're a hero.'"
"If you can drop a millisecond [of latency] off, you're a hero."
This is the kind of attitude that breeds the Scotty types (you know who you are). If you can cut 2 ms, then only cut 1 ms now and save the other for when you really need it. And when the company is going to spend thousands for analysis, then suddenly cut the last 1 ms.
Can anyone explain to me what the advantages of this actually is?
sorry if I sound stupid. It seems like greak to me. I'm just used wireshark etc
www.tdobson.net #### Dare to Dream #### blog.tdobson.net
Now I can get those random stock tips in my email in less milliseconds! I will be rich one day, I will!
I'm waiting for a "-1 somepeoplejustshouldn'tgetmodprivileges" meta-moderation.
No offense guys, but unless you can make something that cuts the ping time in half, we won't be having any good FPS games against the Americans without increasing the ping from 60ms to 250ms or higher. 249ms won't cut it. It just won't.
Get back to /b/. Oh, wait - you can't.
Argh, the buzzwording! It burns us! Make it stop!!
More seriously though, the article might benefit from a little bit more context. As mentioned above, taking 1ms off network latency is meaningless across long connections, where you expect 40ms latency just from the routers, speed of light, etc. Taking 1ms off when microseconds count, when your latency is 5ms, within a system where automated transactions and big money are involved, then the situation is different.
The readers do not recognize the requirements imposed by the environment implicitly!
A more logical reason would be to reduce the possible traffic issues.
If I'm sitting on the network with a 100Mb/s connection straight to the server
First off, the chance of a dropped packet (and delay in re-transmitting) is a magnitude smaller when I'm on the network.
So looking to shave a micro-second/milli-second off of a packet isn't that important or realistic. Humans do NOT make decisions that fast. You'd do better improving the speed of your code or throwing faster hardware at it.
The RIPE NCC's Special Projects group have been offering sub-microsecond latency/jitter/analytical services to ISPs for years. Their data is invaluable and unique, since it measures latency, jitter and packetloss in a single direction (unlike ICMP Ping, which is a round-trip measurement over an asymmetric path) and goes back at least to 2000. The paper claims accuracy to 0.0006 ms, which was good for the time when the product was designed.
Read about the project here and the paper on TTM [pdf] that was presented at the PAM2001 conference.
(This isn't what Corvil do.)
I guess that would depend upon where both points are. One has to be on your network. The other
Now, with Ethernet, one machine can hog the switch (I'll guess that they aren't using hubs). What use is shaving a millisecond off the app if you're still vulnerable to someone else hogging the network at the moment that you're trying to complete your transaction?
So get liquid nitrogen and overclock your processor.
Speeding up the computer running the algorithm is more productive than trying to get your packet through 1 millisecond faster.
I understand that.
I also understand that if you're LOSING because you're one millisecond slower than the competition (or the shift) then you're focusing on the wrong issue.
#1. Re-write your code to be more efficient
#2. Get a faster computer
There is also a market for pet psychics. I'm fully supportive of people selling whatever they can get someone else to buy.
My point is that if you're looking at spending money for a 1 millisecond gain, you've already lost sight of the goal.
There are too many points where delays can happen and almost every one of them is out of your control.
The only time they would not be a factor greater than 1 millisecond is when the process is running on the trading server itself and then the network would be completely removed anyway. And even that is a problem if the trading server has to communicate with any other server.
What is the buffer capacity of the server's NIC?
How long does it take to empty it?
What was the guy just before you doing? Did he fill it?
The same with the network switch.
And that's not even counting a router or everything that can slow down your Internet connection.
if we can't try it, my company won't buy it
i guess they're too just important for us
subject says it all :)
"There is an old network saying: Bandwidth problems can be cured with money. Latency problems are harder because the speed of light is fixed - you can't bribe God."
A beam of light takes roughly 1/7 of a second to travel around the world. That means that if you're playing on a server on the other side of the world, your ping will always be at least 143 ms. That's a hard physical limit: the only way to decrease that time would be to drill a hole through the Earth, or move closer.
You forgot rule 1 & 2.
Electrical impulses propogate much, _much_ slower than the speed of light when run through copper (and perhaps fiber optics since the light beam has to bounce around so much that the path is many times longer?), so your hard limit may be ~143 ms, but only if your signal went through vacuum all the way to the server and back.
The real latency should be actually much higher due to switching or forwarding overhead and any monitoring that the NSA does. 300ms at least.
>Because, when you get right down to it - it's still Ethernet, and so, is still basically CSMA/CA, though the switches, VLANs, etc., hide it for the most part.
When did wired Ethernet become CSMA/CA, and what decade are you in? Collision-based networking? The CD in CSMA/CD has been irrelevant after almost a decade of full-duplex microsegmentation, effectively rendering the MA point-to-point, rather than "multiple access", and throwing out the CS in favour of "empty your buffers as fast as you can".
If you can segment and aggregate on a level equivalent to a High School senior fresh out of Net+, IP over Ethernet still makes more sense than most anything else.
"For every packet [that the appliance records], we compute a signature and a time stamp"
... how about NMAP and Wireshark ...
..
"When it exits on the other side of the WAN, we time-stamp it, and we can correlate the data across the whole network"
Well, doh
'Byrne said Corvil's customer base is "more than 10 but less than 100."'
What ever happened to that perpetual motion outfit
davecb5620@gmail.com
..you just make a Pre-Cabled Domestic Wormhole..
To make your own wormhole:
1. Put your network cables inside garden hoses first as wormholes can be moist environments
2. Take two horizontal clothes washing machines and put them back to back (you can use tumble dryers but its a bit more dangerous - not wet enough)
3. Open the door on each washing machine and take out any socks or coins
4. Drill a hole through each drum and thread the garden hoses through
5. Place a teaspoon of a uranium and a tablespoon of marzipan in each drum. Close tightly!
6. Program each machine to a few seconds before the biggest spin cycle.
7. Wait for each machine to spin up
8. Pull the machines gently apart, you should see twinkling lights between them
9. Don't be tempted to play with the twinkling lights as you'll die.
10. Call UPS.
11. Give them one of the machines.
12. Tell the UPS guy not to touch the twinkling lights
13. Wait for a few days for the machine to arrive.
Propagation time: 4ms - guaranteed.