Latency and Broadband

[grantx]

Baldur,

"You can get a direct leased line to your UK based broker". Of course, you can - if your rich and decadent. I'm trying to be decadent but I need the wealth to support it.

Grant.

 

[blackcab]

Quick tip might be to look at ISPs that specialise in online gaming, reason being that they optimise for low latency (latency being a particularly big factor for gaming). Nildram are probably the best known for that. Check the forums at thinkbroadband.

Also see which SPs have unbundled your local exchange at Samknows. Using a good unbundler will save a handoff or BT wholesale interconnect, removing a link in the chain. Problem then is that you're stuck with that ISP and reliant on their performance.

Most ADSL, either business or residential, is contended, i.e. you're sharing the port at the exchange with up to 50 other customers in the area. You can get uncontended DSL products like SHDSL or some ISPs (Easynet I think are one) do an uncontended ADSL service.

Easynet also do an EFM service (Ethernet First Mile aka Ethernet over copper) which gives up to 10Mbps dedicated bandwidth; it's a straight replacement for traditional TDM leased line tails. I'm not sure if anyone other than Easynet does this yet, it's a new type of service.

If it were me, I'd check who's in my exchange first. Discard the bargain basement providers like Talk Talk and probably Orange and Tiscali, leaving decent providers. Of those, check their services and prices and get as close as you can to Ethernet, SHDSL, uncontended ADSL or business-class, low-contention ADSL, in that order. That would be your primary access connection, and you'll probably want to get a backup line from a different provider, maybe over a different access medium such as 3G data card, WiMax or other type of broadband wireless. Getting a PAYG dialup account can't hurt either as a last resort fallback.

 

[rnicoll]

Most ADSL, either business or residential, is contended, i.e. you're sharing the port at the exchange with up to 50 other customers in the area. You can get uncontended DSL products like SHDSL or some ISPs (Easynet I think are one) do an uncontended ADSL service.

Would just like to point out, business ADSL is contented typically 20:1 instead of 50:1. Uncontended ADSL is also going to be fiendishly expensive, and the exchange generally does a decent job of making sure you get at least some of the connection always...

For ISPs, I've used and can recommend Zen and Namesco. Pipex used to be really good, but I think they're fairly much "meh" these days. Work recommends Demon Internet (who are like, prehistoric in Internet terms), and certainly I don't think there's anything wrong with them.

The budget ISPs (TalkTalk, AOL, Tiscali, etc.) are going to be more of a liability than an assset if reliability and latency are at all issues, certainly.

 

[ofurbaldur]

Baldur,

"You can get a direct leased line to your UK based broker". Of course, you can - if your rich and decadent. I'm trying to be decadent but I need the wealth to support it.

Grant.

You could be supriced how much or little you could pay for a dedicated line.

The advantage is only small. 10ms versus 40-60 ms over internet.

I use Bethere.co.uk as ISP. I think they are just great. I live few hundred meters from the exchange and I get 24mb download and 1.5mb upload.

Fully recommend them.

The better solution is to have both adsl and cable with failover router.

Choosing a broker with a fast reliable gateways might be more important because the speed they route ur orders to the exchanges are different between them.

Good luck with your hunt.

Baldur

 

[maxima]

I haven't done the ping test yet but I have done a speed test. These are the results (I'm using either 4mb or 8mb broadband):

Download at 1952Kbps
Upload: 185Kbps.

I could upgrade to 24mb but would this significantly increase the reception of real-time prices/data?

Grant.

The speed from broadband measuring websites is irrelevant to what you can get to CQG gateway. It could be twice as worse or twice as better or anything really. And it varies during the day.

If you upgrade your broadband it will decrease latency which is what you have to do if you scalp. The cost of upgrade is negligible to the achieved latency decrease.

All those calcs with pings make no sence.

Here are the real calcs:

Imagine 2 identical users - Grant1 and Grant2. They use X Trader (I will give you CQG stats later this/next week). They live in same house and connected to same BT exchange using same service provider. Grant1 has 8Mbps connection and Grant2 24Mbps. They trade same market and they have identical decision making tree and same eye-hand reaction. Therefore we can assume that both Grants will make same decision in response to price change on their screens and send an order with same delay after price change materialised on their screens.

From my experience X Trader takes 1Mbps in average (it oscillates between 0.5 and 1.5Mbps for me).

Now imagine that (as both Grants use same gateway and same ISP) the price change (which will later on trigger order to be sent by both Grants) arrives to the BT exchange at same time and data forks to two different ADSL connections - to Grant1 and Grant2.

To reach Grant1 PC data need 1mbps of load/8mbps = 1000ms / 8 = 125ms
To reach Grant1 PC data need 1mbps of load/16mbps = 1000ms / 16 = 62.5ms

Both will react with the same delay but Grant2 will send order 62.5 ms earlier than Grant1.

Further - Grant2's order will reach BT exchange even quicker than Grant1's one as 24Mbps broadband means ADSL2+ Aneex.M presumably and in this case uplink is considerably faster (I have 1.5 Mbps) than for ADSL (often 256Kbps). Although order as a data is very small but still few milliseconds difference will be added up. I guess the difference can practically be another 2.5 ms.

Overall Grant2 placed order 65ms earlier than Grant1.

And this luxury cost you pretty much the same money (plus minus 5 quid a month).

Router doesnt make difference as there is nothing to route. I would estimate that Cisco will switch packets few hundred nanoseconds faster than cheap router for home.

 

[north5]

I don't know if you have an automated system - I do - and I have hosted it on a server with an ISP. That gives it about the best internet connection I could get and also removes most of the issues you get with home adsl - lines going down etc. Then I just remote into it - also means I am pretty free to roam as I please and check in with mobile adsl if I want.

Works well for me.

 

[rnicoll]

From my experience X Trader takes 1Mbps in average (it oscillates between 0.5 and 1.5Mbps for me).

Good lord, what is it doing in there? Okay, a single price is 8 bytes, 64 bits. 1Mb/s is 1073741824 bits, assuming you're calculating as 1024x1024x1024 (and frankly how people calculate 1Mb/s these days more depends on the weather than anything else), or
16,777,216 prices. Per second.

Now, okay, you've got network overhead, control data, resends in case of packet loss, etc. but what on earth are they doing in there?

Are you sure you don't mean 1-1.5Kb/s? At which point latency is going to dominated by the amount of time it takes the switching gear to route the packet to you, rather than your bandwidth...

Edit: No, ignore me. It's 1024x1024, 1048576, or 16384 prices. Still a lot though.

 

[maxima]

Good lord, what is it doing in there? Okay, a single price is 8 bytes, 64 bits. 1Mb/s is 1073741824 bits, assuming you're calculating as 1024x1024x1024 ...

Yes. I know the maths. And that what I see in real life.

Once I had my main line down and I used BT @ 6Mbps and I had CQG and XT running in parallel and I had CQG warnings about poor network performance and it froze several times.

 

[rnicoll]

Yes. I know the maths. And that what I see in real life.

Once I had my main line down and I used BT @ 6Mbps and I had CQG and XT running in parallel and I had CQG warnings about poor network performance and it froze several times.

I'd suspect it's streaming the data around as strings. It seems remarkably popular these days.

I cringe that all these "fast" systems are streaming data around in TCP with no thought for packet size. UDP packets, and ensuring each packet doesn't need to be split to get under MTU, would zoom past this nonsense.

End rant.

 

[grantx]

Max,

I can run my seperate chart feed, Excel with dde's and CQG - and order execution is so quick, I cannot time it. This via 8mb broadband. CPU load factor (if that's the correct term) never exceeds 10%. So why does it take a long time to load T2W?

Grant.

 

[maxima]

these things are not related to each other. cqg fill time, cpu and t2w website.

latency for me trading US markets is something I can note with bare eye. But if I traded Eurex I probably wont be able see it hence you cannot evaluate is it fast or not fast until you measure it somehow precisely.

CPU load is not regarded in any previous discussion just because it is different plane parameter. My first answer was to your question - could you make better trading if you would upgrade broadband. The answer is - definitely yes. CPU is irrelevant in this case.

Websites are not the same service as CQG data feed. WWW is not the same as Internet. The website is slow because it is hosted in Washington DC. Perhaps not withing the fastest hosting facility (all of them are in NY).

When you back from sunny French coast - drop by in London, lets get a pint - I will draw you diagramms and evey detail.

But the short advise - upgrade your internet. It holds you back more than PC. In other words - invest in telecommunications rather than into hardware. Simple.

 

[grantx]

Max,

Close your eyes when you're trading US.

Upgrade my internet - you mean from 8mb? But I thought the limiting factor was physical telecoms line, ie upgrading will not make any difference.

I'm sure we could meet for a pint next time I'm in London.

"Simple"? For whom? Sorry, a bit formal that - Who for?

Grant.

 

[maxima]

Read my first post in this thread - thinner broadband adds up to bad ISP line. If you get wider broadband you reduce latency.

no matter how slow your ISP - you make it worse having 8mbps broadband (in comparison to having 24Mbps).

 

[dcraig1]

Read my first post in this thread - thinner broadband adds up to bad ISP line. If you get wider broadband you reduce latency.

no matter how slow your ISP - you make it worse having 8mbps broadband (in comparison to having 24Mbps).

Your ADSL speed mainly depends on distance to the exchange. If you are more than 1km from exchange, then it is unlikely that you will be able to get 24Mb/sec.

The ADSL modem negotiates with the DSLAM at the exchange to agree upon the highest speed achievable given the signal to noise ratio and attenuation of you phone line. According to the plan you subscribe to, your ISP may limit this further.

All this has virtually nothing to do with latency.

Your line speed only really matters if you are using up a significant portion of your bandwidth which is pretty unlikely for a futures trader monitoring a couple of instruments.

 

[maxima]

Your line speed only really matters if you are using up a significant portion of your bandwidth

that was my main point.

which is pretty unlikely for a futures trader monitoring a couple of instruments.

I measured that for myself and this is precisely in opposite.

 

[dcraig1]

that was my main point.

I measured that for myself and this is precisely in opposite.

Which instruments and what are the figures ?

 

[maxima]

From my experience X Trader takes 1Mbps in average (it oscillates between 0.5 and 1.5Mbps for me).

.

 

[maxima]

Measured CQG Trader - takes 175Kbps

 

[nine]

Actually you get negligible reductions in latency when your pipe gets really big.

You give 8Mbps vs 24Mbps as an example. Packetization delay for a 1000 bit packet (most packets from/to your broker are probably smaller is just 1000/8million vs 1000/24million seconds. That sounds a lot but its 0.000125 (0.12ms) vs 0.0000417 (0.04ms) so the difference is 0.08ms).

When you do your ping time to your broker its probably 50 to 180ms (mines in a different country) so if you take a 50ms round trip and then consider the effect of adding 0.08ms twice (its a round trip) then you can see that 50ms vs 50.16 ms isn't a lot. Its about 0.3% so its in the noise.

 

[maxima]

Actually you get negligible reductions in latency when your pipe gets really big.

You give 8Mbps vs 24Mbps as an example. Packetization delay for a 1000 bit packet (most packets from/to your broker are probably smaller is just 1000/8million vs 1000/24million seconds. That sounds a lot but its 0.000125 (0.12ms) vs 0.0000417 (0.04ms) so the difference is 0.08ms).

When you do your ping time to your broker its probably 50 to 180ms (mines in a different country) so if you take a 50ms round trip and then consider the effect of adding 0.08ms twice (its a round trip) then you can see that 50ms vs 50.16 ms isn't a lot. Its about 0.3% so its in the noise.

well. I just tried to help. I used to work as a telecom engineer and software developer and was highly paid to know things like that. You are happy to trade like you do - thats the main thing. Happy trading and nice weekend :clover: