Leased line question

[Tomh432]

Hi,

I asked this on another forum and was advised to post here as apparently at least 1 of you is very knowledgeable in this area! I'm getting conflicting information from my Leased Line supplier and IT support company and can't find a definitive answer online.

We have a 100mb leased line

Our IT support company is saying that we should be able to do 100mb download and 100mb upload at the same time.

The company that supplies the line says although we can do 100mb up and 100mb down, it's only a maximum total 100mb at any one time. So could be 99mb up and 1mb down, or 99mb down and 1mb up but can only total 100mb and they say that this is industry standard.

I found statements online like "upload just as fast as you download" from Virgin and "a leased line is synchronous so you'll get the same transfer speeds in both directions" on leasedline.co.uk but our provider are saying that those statements don't say you can do it at the same time. They say that they're differentiating from broadband where you have different upload and download speeds.

I can't find anything that specifically states either way so is anyone able to advise what industry standard is? Ideally with something concrete to back it up if possible!

Thanks in advance for any help

[nickd01]

From my understanding there is no 'standard' - it's all about what you agree when you sign the contract.

We have, for example two point-to-point lines and they're both symmetrical (SDSL and not ADSL I beleive) so get 100Mb and 1Gb down and up at the same time.

Thinking further, how do you know you don't have 100/100 capacity?

Edited by nickd01 on Wednesday 11th January 16:59

[wombleh]

If it's a full duplex link then it should carry that bandwidth up and down simultaneously, although allowing for protocol overhead you might only hit 80-90Mbps. Gigabit Ethernet will do that and isn't called 2Gbps Ethernet because it's full duplex, although vendors have tried marketing tricks like that in the past!

Agree with above on not really having one standard, there's a few different technologies for leased lines and the providers may be throttling/policing so the way to know what you should get is to check the contract. Although if you can name the actual product here then we may be able to help.

Edited by wombleh on Wednesday 11th January 17:18

[theboss]

It's going to depend on the provider and the underlying technology used but if its a true Ethernet based service it should be full duplex.

I have a 1Gbps leased line based on Openreach EAD to my premises which is definitely full duplex and in fact that's documented by Openreach here under section 3.4:

https://www.openreach.co.uk/cpportal/content/dam/c...

Bear in mind if you are saturating bandwidth in one direction this will still generally impact transfers in the other direction, but I did just run a test and my sustained upload dropped back to about 600Mbps whilst I was downloading at 985Mbps.

I would be willing to bet the underlying service should be FDX but your provider is manually fixing interface duplex settings on a router somewhere with the result you have a half-duplex link somewhere in the chain. Can you check the link from whatever device of yours is connected to the ISP's equipment and see if its half or full duplex?

Edited by theboss on Wednesday 11th January 17:22

[ffc]

Tomh432 said:

Hi,

I asked this on another forum and was advised to post here as apparently at least 1 of you is very knowledgeable in this area! I'm getting conflicting information from my Leased Line supplier and IT support company and can't find a definitive answer online.

We have a 100mb leased line

Our IT support company is saying that we should be able to do 100mb download and 100mb upload at the same time.

The company that supplies the line says although we can do 100mb up and 100mb down, it's only a maximum total 100mb at any one time. So could be 99mb up and 1mb down, or 99mb down and 1mb up but can only total 100mb and they say that this is industry standard.

I found statements online like "upload just as fast as you download" from Virgin and "a leased line is synchronous so you'll get the same transfer speeds in both directions" on leasedline.co.uk but our provider are saying that those statements don't say you can do it at the same time. They say that they're differentiating from broadband where you have different upload and download speeds.

I can't find anything that specifically states either way so is anyone able to advise what industry standard is? Ideally with something concrete to back it up if possible!

Thanks in advance for any help

I'd be interested to know what protocols they are using that know what you are transmitting from your end and thus can restrict what they send back.

A simplex circuit would only allow traffic in one direction at once which a duplex circuit allows traffic simultaneously in both directions. To be able to restict the total bothway throughput would require each end to report its tranmission rate to some form of device that can rate-limit transmission at the other end so you only get 100mb in total.

It's not a technology or service type that I've heard of before.

[fourstardan]

What router is on the end? Could be a config issue and someone trying to fob you off on the ISP side.

[theboss]

fourstardan said:

What router is on the end? Could be a config issue and someone trying to fob you off on the ISP side.

That's exactly what I suspect as well. I would put a tenner on there being a half-duplex link somewhere in the path because of a misconfigured interface.

[Captain_Morgan]

Tomh432 said:

Hi,

I asked this on another forum and was advised to post here as apparently at least 1 of you is very knowledgeable in this area! I'm getting conflicting information from my Leased Line supplier and IT support company and can't find a definitive answer online.

We have a 100mb leased line

Our IT support company is saying that we should be able to do 100mb download and 100mb upload at the same time.

The company that supplies the line says although we can do 100mb up and 100mb down, it's only a maximum total 100mb at any one time. So could be 99mb up and 1mb down, or 99mb down and 1mb up but can only total 100mb and they say that this is industry standard.

I found statements online like "upload just as fast as you download" from Virgin and "a leased line is synchronous so you'll get the same transfer speeds in both directions" on leasedline.co.uk but our provider are saying that those statements don't say you can do it at the same time. They say that they're differentiating from broadband where you have different upload and download speeds.

I can't find anything that specifically states either way so is anyone able to advise what industry standard is? Ideally with something concrete to back it up if possible!

Thanks in advance for any help

To be fair op I think you were advised

Captain Morgan said:

I recall over on piston heads in their computing sub forum reasonably resently there was a thread about leased lines & a line broker got involved, it might be worth trying to google the thread & contact him?

Either to help understand if your provider really is a outlier, if he’s aware of any others that do this or just what options you have come renewal.

Still…

The thread I recalled.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Tomh432]

Captain_Morgan said:

Still…

The thread I recalled.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

I did have a search but the latest one I found was from 2021 so decided to start another thread, looks like this one will help though so thanks for pointing me in the right direction

[simon_harris]

who is buying a 100mb leased line in this day and age anyway? I wouldn't bother with anything less than a 1gb connection.

[Sixpackpert]

simon_harris said:

who is buying a 100mb leased line in this day and age anyway? I wouldn't bother with anything less than a 1gb connection.

We did a year ago. Budget and requirements meant we didn’t need to spend the extra for a 1gb line. Can upgrade the speed at any time but just not needed at the moment.

The best we used to get was 6mb down and 0.9 up so 100/100 is a vast improvement!

[Tomh432]

quinny100 said:

Firstly, get a new IT support company because if they’re clueless as something as fundamental as this they probably aren’t much good at other stuff.

This is actually something best explained using the OSI model. Forget all this talk of protocols and standards because the answer is Layer 1 stuff - the physical connection.

Any physical link will have a link speed negotiated or set between the hardware at each end, typically 100Mbps, 1G etc. That determines the data transfer rate or bandwidth available across the link. It doesn’t matter which way the traffic is flowing - you will never exceed the physical link speed, so their assertion you should get 100Mbps down and 100Mbps up simultaneously is utter nonsense.

Full duplex is the ability for a devices to send and receive packets simultaneously, but has no direct relationship with bandwidth as such. The nature of network traffic is primarily 2 way, TCP is the most common traffic type and that requires the receiver to acknowledge packets back to the sender as it receives them, so with a half duplex connection you end up with a lot of dead time whilst the network interface is waiting to send or receive the next packet. Full duplex allows more efficient use of the link, but doesn’t allow the traffic to move any faster per-se.

We've used the IT support company for years and they have usually been really good, so I was leaning toward them being right - although to be fair their answer was the one I wanted to be right so there was some bias there! There's a lot of conflicting answers on here, can you link to anywhere that states what you have?

To answer question a few others have had - We have 2 offices both with 100mb leased lines on 1Gb bearer set up as an MPLS by the line provider, which then has part "sectioned off" for data replication between the sites. The IT provider have then used the MPLS to set up data replication between the 2 sites and set up firewalls to restrict the data so not to over utlise the line. It keeps hitting the bandwidth limit which has caused some problems. They say they've set up loads of other clients like this and it's always been fine, and I believe them but wonder if all the others just had plenty of spare bandwidth?!

The routers at each end are Juniper SPX300s - but these are controlled by the line supplier I don't think I can look at the configuration? I have had a look through the link theboss sent above and I might put that to the supplier and see their response, but they seem to be unwilling to move from their "that's how these lines work" response.

I know people have said there are difficult technologies at play, but is it reasonable to expect full duplex unless otherwise stated? When we compared costs I thought we were comparing like for like services and it's not like this company were significantly cheaper than all the others!

Thank for all for all your input

[Tomh432]

simon_harris said:

who is buying a 100mb leased line in this day and age anyway? I wouldn't bother with anything less than a 1gb connection.

We got it about 3 years ago on a 5 year contract - seemed like a great deal at the time and unthinkable we'd need more bandwidth! Since then for various reasons the amount of data we're producing is had increased a lot

[simon_harris]

if it is that new i would suspect it is 100mb over 1000mb line and your provider is throttling you.

[Dave Hedgehog]

Sixpackpert said:

simon_harris said:

who is buying a 100mb leased line in this day and age anyway? I wouldn't bother with anything less than a 1gb connection.

We did a year ago. Budget and requirements meant we didn’t need to spend the extra for a 1gb line. Can upgrade the speed at any time but just not needed at the moment.

The best we used to get was 6mb down and 0.9 up so 100/100 is a vast improvement!

it always makes me laugh how expensive commercial internet is compared to domestic, I'm paying £65 a month for 900/300 and with the amount of media downloads and the game servers i run my usage is just as high as an avg commercial user

[Mr Pointy]

Dave Hedgehog said:

Sixpackpert said:

simon_harris said:

who is buying a 100mb leased line in this day and age anyway? I wouldn't bother with anything less than a 1gb connection.

We did a year ago. Budget and requirements meant we didn’t need to spend the extra for a 1gb line. Can upgrade the speed at any time but just not needed at the moment.

The best we used to get was 6mb down and 0.9 up so 100/100 is a vast improvement!

it always makes me laugh how expensive commercial internet is compared to domestic, I'm paying £65 a month for 900/300 and with the amount of media downloads and the game servers i run my usage is just as high as an avg commercial user

But what is the guaranteed availability & repair time for your service?

[SteveKTMer]

First thing is to identify exactly what is using the bandwidth - then is it what you expected ? Look at the distribution over the lines and see what's being used and where. I'd be very surprised if your IT firm couldn't give you this but if not ask them to set this up. Juniper routers will be able to help here.

However the lines are configured or why can then be looked into. If they are leased lines they are likely to be on a gig bearer, so you can increase the speed from 100meg to 200 or 500 or the full gig - depends on contract. (If you want more bandwidth you might need to upgrade the firewalls too)

Also check if the firewalls are running IPS or other CPU intensive activities on the data, or if they have VPN and IPS and other services running which might eat into your CPU which can limit speed.

If you want to run your own monitoring a product called PRTG is very easy to set up and gives you 100 free sensors before you need to pay anything. A sensor is a switch port or a router port and you can then measure bandwidth by protocol.

Once you have the info you'll know what to do next.

[GuyW]

I'd also get it checked/confirmed that any firewalls & switches don't have any ports set to half duplex, or anything equally daft.

[quinny100]

Tomh432 said:

We've used the IT support company for years and they have usually been really good, so I was leaning toward them being right - although to be fair their answer was the one I wanted to be right so there was some bias there! There's a lot of conflicting answers on here, can you link to anywhere that states what you have?

To answer question a few others have had - We have 2 offices both with 100mb leased lines on 1Gb bearer set up as an MPLS by the line provider, which then has part "sectioned off" for data replication between the sites. The IT provider have then used the MPLS to set up data replication between the 2 sites and set up firewalls to restrict the data so not to over utlise the line. It keeps hitting the bandwidth limit which has caused some problems. They say they've set up loads of other clients like this and it's always been fine, and I believe them but wonder if all the others just had plenty of spare bandwidth?!

The routers at each end are Juniper SPX300s - but these are controlled by the line supplier I don't think I can look at the configuration? I have had a look through the link theboss sent above and I might put that to the supplier and see their response, but they seem to be unwilling to move from their "that's how these lines work" response.

I know people have said there are difficult technologies at play, but is it reasonable to expect full duplex unless otherwise stated? When we compared costs I thought we were comparing like for like services and it's not like this company were significantly cheaper than all the others!

Thank for all for all your input

Disregard what I posted previously because it was rubbish and I was unfair to your IT Support company. Shouldn’t post in the middle of the night!

At a theoretical level on a full duplex Ethernet connection you can get line rate in both directions. Ethernet connections have separate transmit and receive lines on different strands of the copper or fibre cable (or different wavelengths of light on single fibre connections).

Your ISP is also correct that Internet connections are usually sold as a total bandwidth - with the transmit and receive added together.

[smack]

Tomh432 said:

The routers at each end are Juniper SPX300s - but these are controlled by the line supplier I don't think I can look at the configuration?

No such thing as a Juniper SPX router. It will be a SRX300, which is a Firewall and they have more than enough performance for a connection of your size, unless someone has misconfigured it and/or balls up IPS settings which can cause problems. But as your IT Company manages this, they should tell how it is setup.