A Crash Course on Network Bandwidth Metrics? 108
Kind of Blue asks: "I work for a small software development company in India, providing development services for a company in UK. We connect to the UK client through VPN; and our correct staff strength is around 13. We are going in for a major upgrade in our internet connection — and owing to the size of the firm, cannot afford the services of a networking expert/consultant. Hence I, a layman, have been asked to look into the matter and decide on the ISP and the bandwidth. I have a vague idea about the required bandwidth — it must be around 512 kbps(remember, it's India I am talking about!) and must be a persistent connection, since we use source control softwares connecting to servers in the UK.
There doesn't seem to be a 'networking for dummies' kind of resource on the web. No one seems to talk of network metrics anywhere. So, can Slashdot give me a crash course in what I need to know?"
"Our present ISP gives us a DSL connection of 512 kbps on 1:4 sharing. There are frequent disconnections; and hence loss of work while code check-ins. As we are increasing in strength, I am also looking at more bandwidth. But what bamboozles me is how are these things measured? Will I get a better bandwidth if I take a 512 leased line on 1:2 sharing? When the staff doubles, should I upgrade to a 512 connection on 1:1 sharing or must I take 1 Mbps on 1:4 sharing?(There's a huge price gap between the 2 here in India) In any case, how does one decide the optimum bandwidth required for a bunch of 15 developers on VPN and Source control?"
Measure twice, cut once (Score:5, Informative)
it must be around 512 kbps(remember, it's India I am talking about!) and must be a persistent connection, since we use source control softwares connecting to servers in the UK.
Have you actually measured how much bandwidth your source control software application consumes? To me that'd be the very first step, before you look into upgrading from one voodoo number to another. Real data is very often the key to good decisions.
Re:Measure twice, cut once (Score:5, Funny)
Re:Measure twice, cut once (Score:4, Funny)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Re:Measure twice, cut once (Score:5, Funny)
Re: (Score:1)
Re: (Score:1)
Re: (Score:2)
Re: (Score:1)
Re:Measure twice, cut once (Score:5, Informative)
For the kinds of usage patterns that source code control systems generate, latency is most likely going to make a bigger difference.
The classic example is the old saying, "Never under-estimate the bandwidth of a van full of tapes." It's true - the bandwidth of such a system would be incredible compared to what most people are used to working with. It's just that the latency for, say, a connection between Inda and the UK would be measured in days.
Re:Measure twice, cut once (Score:5, Informative)
The internet is not a big truck! It's a series of tubes!
Re: (Score:2)
Re: (Score:3, Funny)
Yeah. Tubes. [wikipedia.org]
Re: (Score:1)
The internet is not a big truck! It's a series of tubes!
I like what passes for "Informative" on Slashdot.
Re: (Score:1, Funny)
Re: (Score:1)
mod parent up. what parent is trying to say is related to the way TCP manages its congestion window. If you're facing high latency in the link to your UK office (which is likely, given the distance metric), the RTT will be high and TCP will slice its congestion window in half -- so even if you were to have "sufficient bandwidth" (whatever that means!), TCP wouldnt let you f
Also (Score:5, Funny)
I'm trying to outsource your jobs. However, I don't know all that I need to know. Would you mind providing free training in your spare time for your replacement?
OTOH: you probably don't need as much speed as you do reliability. I would guess that an unsharing situation will work better for you.
You might, over the short term, insert an extra hop in your network in front of the ISP hop, and measure avg bandwidth there over the course of a business day. As long as you have enough total bandwidth / second to match your typical usage (allowing for some margin, and expected growth) in a business day, all you'll cope with is some latency.
Re: (Score:2)
Dear Slashdot, how do I measure bandwidth usage...?
Seriously, I think that's a pretty basic point and the fact that he didn't bother says a lot about the likelihood of this mission being a success.
He can't hire a consultant for 1 DAY !! to figure this problem out properly, instead of throwing money at it and hoping it works? Good freaking luck.
1 day - try 2 hours (Score:2)
My other piece of advice is similar to what I've already seen: Ignore bandwidth, look for reliability. As recently as 2003 we had 4 users in the US on a single 56k line - and really, it was fine if you weren't trying to download big files. But it was a rock solid 56k that didn't lose any packets.
If you have actual DSL disconnect
Re: (Score:2)
I'm trying to outsource your jobs. However, I don't know all that I need to know. Would you mind providing free training in your spare time for your replacement?
I think he should insert two, four, or even eight hops in between his network and the ISP. Actually, maybe it should just be 60 extra hops, since we all know that if you exceed your TTL (stands for "Takes Too Long"), most ISPs will increase your bandwidth to compensate anyway. Go ahead, string up those routers!
Re: (Score:1)
Seems silly to me. (Score:5, Informative)
Note: SVN/CVS/SourceSafe/whatever can probably do this already, IANAEIVS (I am not an expert in versioning systems).
Re: (Score:2, Informative)
Re: (Score:2)
I'm neither promoting nor denigrating such practices, merely relaying observed behavior.
Subversion..... (Score:4, Informative)
Staff levels (Score:1, Informative)
So after adding in your incorrect staff, you get a total of?
How much data are they pushing onto the source control server? Why not just move the source control server to India?
Contention ratios only help to ensure that you get the full 512Kb/s, it won't increase your reliability I wouldn't think. You will have to increase your total bandwidth size, not just change your contention ratio when you get more staff.
Re: (Score:1)
In any case, how does one decide the optimum bandwidth required for a bunch of 15 developers on VPN and Source control?"
So after adding in your incorrect staff, you get a total of?
Comon, it says it right there. 13 correct staff + 2 incorrect staff = 15 total staff
Re: (Score:2)
I have karma to burn... (Score:3, Interesting)
Maybe you can outsource this project to the west since there are plenty of very well experienced people who know this stuff who could use the work.
I don't hate India or Indians, but it will be a cold day in Hades before I give assistance to a shop whose only purpose in this world is to displace jobs formerly occupied by my neighbors.
India is importing western IT staff. (Score:3, Interesting)
Re: (Score:1)
Thanks, but no thanks. India is definately on the list of places I'll never live, regardless of the job market or pay scale.
Re: (Score:3, Insightful)
Seriously, I'm not convinced by the economists that our current import/export situation is a good thing, and I've always been a big Buy American advocate, but I find intense irony in the fact that my IT coworkers seem to all think I'm retarded for buying a Ford, but can go on endlessly about outsourcing programming to India.
I don't know Yonder Way, and maybe this doesn't describe him, but I've always been ama
Re: (Score:3, Interesting)
Sorry, I don't make enough to buy one of those. You'll have to pick between my 1981 Ford or my wife's 1984 Dodge "K car".
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Ironically, many "US" cars are made in Mexico or Japan, or are simply rebranded foreign cars. You can look at the the VIN next time you're shopping for cars.
1st character- Identifies the country in which the vehicle was manufactured.
For example: U.S.A.(1or4), Canada(2), Mexico(3), Japan(J), Korea(K), England(S), Germany(W), Italy(Z)
http://www.autoinsurancetips.co [autoinsurancetips.com]
Me too (re: I have karma to burn...) (Score:2, Interesting)
don't blame "us" - "we're" just the sheep. Blame the criminals who legislated themselves a banking monopoly - that'd be the quasi-public "federal reserve" system.
Federal Reserve "prints" money to pay for the budget deficit. Printing money (monetary inflation) causes price inflation, and price inflation causes producers of goods to cut corners to keep their costs down, hopefully just a little while longer than their competitor.
In recen
Re:Me too (re: I have karma to burn...) (Score:4, Insightful)
Nope. Old money families usually own resources, not dollars. If you own a diamond mine worth $3 million today, and the dollar deflates by 100 - now you own a $300 million diamond mine. You've lost nothing. Same with stock, pork futures, or real estate.
The rich usually stay rich.
However, your $70k mortgage balance is still only $70k, while the value of the house is now $7 million. Any debt you (or rich people) hold would become trivial to pay off.
But... (Score:2)
Re: (Score:1)
Not sure what PA is supposed to mean.. per annum?
Assuming that's what you meant.. most adjustable rate mortgages (ARMs) have both an upper-limit rate and a maximum increase per year. For example, I have a 4.50% ARM that can adjust 1% per year, cap of 12%.
Re: (Score:2)
Like 40 year loans, loans where you only pay interest, unless you ahve a very precise need for one, avoid the,m. Hell avoid 30 year loans and go for 15 year loan.
BTW, move into a fixed as soon as you can, interest rates are rising very soon, and the housing bubble has popped.
In the UK (Score:2)
Re: (Score:2)
Re: (Score:3, Insightful)
Actually, forget that.
Re: (Score:3, Insightful)
Re:I have karma to burn... (Score:5, Insightful)
You see, his neighbor (in this implied situation) didn't lose his job because he done something wrong, he didn't lose it because some one better came along and could do it more efficiently. He didn't lose it because some produced a product cheaper from a better process. He lost it because some one is exploiting the difference in the econemy between two places.
If the dollar was the same value everywere and a gallon of milk cost the same in india, china, UK or USA, then the job would never have left the country. But the reality is that we are exploiting third world countries and lessor developed countries because they are lacking the development of econemy that the rest of the world has. We are seeing people working for pennies on the dollar mostly because when converting the penny to the other currency, it is valued more like a dollar.
Now, the right that is implied is were a company wishes to compete in one location but derive it's labor supply another. We aren't importing the product, just the labor for the product. In the real world, minimum wage laws, unions and trade contracts would place limits on the lowest a company can pay the employee but when outsourcing to other countries, they are getting around this. Imagine the government allowing mexicans to come to america legaly with the intended purpose of working for less then minimum wage at factories were normal workers get $12.00 per hour. It would never last (on a legal basis) but outsourcing is basicly allowing this to happen.
It might not exactly be a right to work more then a obligation for the company to hire employees in the country that they are set up in and doing business in. If the company wants to set up shop in that arbitary geographical location then let them hire all they want from there. Fireing some one in the location were you make your product, profits and public image in order to exploit the difference in currency or econemy in another location doesn't seem proper. If you think it's ok to screw the people over in the area making the bread and butter for your company then more power to ya. I'll save you a spot in the unemployment line when you find out your job has been replaced by someone doing it for 40 cents an hour because the working conditions and monetary value of the currency in some other country is so different. At least japan decided to make plants in america when the foreign cars cost so much less then american cars because the value of the yen.
Re: (Score:1)
Re: (Score:2)
Re: (Score:1)
Re: (Score:2)
Well, in this case, the person living in the country to which the job was outsourced did
Re: (Score:2)
Well first off, let me begin by saying I agree with most of what your saying. I don't have any issue with buying something manufactured in some other country. Even if it is something that is part of something else assembled in your country. What I have the problem with is farming the jobs out to otherwise equal paying paersons but exploiting the weaknes of thier econemy and still trying to maintain they are A local company.
If you break it down to the buying power of the persons salery, y
It's worse than you think (Score:2)
http://techpolicy.typepad.com/tpp/2004/03/tax_brea ks_for_.html [typepad.com]
http://www.americanprogress.org/site/pp.asp?c=biJR J8OVF&b=32409 [americanprogress.org]
These were high up in Google, that's my only endorsement of these sources. It was a hot issue in 2004...
Re: (Score:2)
If a company makes money from offshoring, then they are going to be paying taxes were ever they off shore. Why should they be double taxed because they have a presence in america? This is the only fair way to have a mumtinational corperation do business in multiple countries. The tax will just be pass
Re: (Score:2)
Joe India may have equal rights to that job.. but people have a vested interest in a) keeping their own job and b) keeping their own economy healthy.
Re: (Score:2)
If a company wants to exploit economic imbalance, then they should not get any tax breaks or tax write offs. Then will see outsourcing come to an end.
Re: (Score:2)
I know there are a lot of great IT people in India, but there are also a lot of crap ones. I take from this that the good ones are employed, and the search for more and more IT programmers is coming up
Quick thing on sharing (Score:4, Informative)
Yes and No. Right now you are setup on a 512K/s line, shared with up to 4 other customers. This means that if Customer A is using 400k/s, and Customer C is using 100k/s, then customers b and c get to share 12k/s. (without getting into the discussion of prioritizing and QOS, I'm way oversimplifying) Or, depending on the setup, each of you might be setup to only get 128k/s when all of you are using your connection. Now, if its the first case, and you have one other customer that is hogging all your traffic, then you will benifit from moving to a 1:2, or even just getting rid of them on the same circuit. However, the only way to be sure that you have 512k/s if you need it is to make sure you have your own connection, and a garuntee from the ISP. (in the US, these are called "Business class" DSL circuits in many areas) It will be MUCH more expensive.
reliability and bandwidth are not always related (Score:2)
Most times it depends on your ISP and their upstream ISPs' network, quality of service, etc.
Note: it is possible you are reaching your real bandwidth limit (what the ISP makes available to you) at different times which causes delays resulting in timeouts. Might be volume of traffic over the VPN link or it might be non-VPN traffic to the rest of the internet.
If you want more bandwidth (hedged bet for the future) and better reliabil
Latency: the other metric (Score:2)
We switched to a new provider (actually had to, the old one was in bankruptcy) and people were stunned by the improved sp
Re: (Score:1)
Additionally, the local DNS server may help to reduce the amount of bandwidth that is being used by reducing the number of machines that are going out for DNS lookups.
Pony up and pay (Score:5, Insightful)
Enjoy the answers.
When you could have asked.... (Score:5, Funny)
Then; Take the number of connections at your end before your connection was severed, and add that to 'half' the number of connections when your ISP's server/connection maxed out, multiply by the number of toilets in your office, and divide by Pi.
That's easy... (Score:2, Informative)
Re: (Score:2)
Why don't you just outsource your development work to the U.S.? Then you won't have to worry about bandwidth.
how so? are US - UK pipes free?
So (Score:1)
Re: (Score:2)
Re: (Score:2)
I bet that his company is also doing work for American companies.
Maybe, maybe not. The UK company itself may be contracting for a USA company. They might (but probably not!) be contracting for an Indian company.
And if not his company there are lots of other indian companies that are, so why help them out when they are stealing our jobs.
Ah, there's your point. He's Indian, therefore he's ripping me off. Even if he's not doing it to me personally, he's guilty by fact of his employment in India.
Of
Disgusting prejudice. (Score:1)
Re: (Score:2)
a) The contractors were working in the same physical office we were so communication with them was easy,
b) All of them had impressive skillsets and a considerable amount of specific application knowledge, and
c) The contractors actually solved a very real problem our organization had (not enough knowledge
Re: (Score:1)
I suspect that 'management' are not the only people to blame. Perhaps the entire U.S. system is collapsing upon you: shareholders want better returns; politicians want to return to office and so are
Re: (Score:2)
I completely agree. Nevertheless, such incidents can result in misdirected feelings towards other parties, and that persons in the former situation I described are a lot less likely to be annoyed at the idea of contractors than folks in the latter situation. I'm not saying it's justified, only possible.
I personally
here is the reason (Score:2)
Managment was looking at replacing you with them.
When training someone who will be taking your job, train them badly, foist all problems on them, communicate with them at a time when it seems reasonable, but in reality it isn't so they are always the delay.
You owe nothing to a company that will drop you like a hot potato, and you own nothing to whome ever they will replace you with.
Fight for your job, becau
Re: (Score:1)
Re: (Score:1)
Thanks for explaining your situation.
Pricing (Score:3, Insightful)
Welcome to the world of business. Are you starting to understand why we charge as much as we do outside of India? It's because we have to support our business infrastructure and still make a profit for all our effort! Don't like it, go back to India. Oh wait...
Tell (Score:4, Funny)
Wait. (Score:2, Insightful)
Re: (Score:1)
Re: (Score:1)
It's not all about bandwidth (Score:2)
So also consider the "bandwidth delay product"[1] to where you're connecting to and compare this to your recieve window size. Consider checkking to make sure increasing your recieve window size won't get you better performance. This needs to be done at the end of the connection that's recieving the data, which for
Ask Chandler Bing from Friends (Score:2)
Didn't he have to compile numbers for WEekly Network USage and Annual Network USage?
Re: (Score:2)
Nope. The WENUS - Weekly Estimated Net Usage Statistics. Net being gross minus expenses; nothing to do with networking.
Man, I watched too much of that show..
Is this about check-ins ? (Score:1)
Is this the key reason why you need a VPN?
[BTW, I hope that you are not using MS SourceSafe...]
Have you considered alternate revision control systems?
On the (not too expensive) commercial side, I am a fan of Code Co-op, from http://www.relisoft.com/ [relisoft.com]. I've used it with a development team in China a few years ago, and they were definitely worse-off than you. Free trial available for download.
Simple (Score:2)
Follow the procedure, you want to do a network latence repair know has 'partitioning'. It splits the bandwidth up among applications accross your hard drive. This will dramatically reduce bandwidth.
You versioning system is going to be a big drain, I suggest starting with that one.
Re: (Score:1)
Well, let's give them a fighting chance at least. Ok, here's what I do to estimate bandwidth needs: Minimum bandwidth x number of users @ peak time. In your case- I would say you need a 1.5 MBit T-1 line or better. If you can't afford to do that in your current contract, then you need to renegotiate your contract for more money.