EFM - Speed Vs Bandwidth

satanicguardian

satanicguardian

satanicguardian

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Solihull
Hi guys, I'm trying to get to grips with this concept - it has perplexed me for quite a while now. I think it's a fairly common misconception that bandwidth relates to your download speed on things like speedtest.net

I believe I've come to a very vague understanding using dodgy diagrams in pen and some crap analogies.

53100597-0864-46b3-9ce7-11b62367c2af.jpg


The left diagram labelled A (I forgot to label the right one!) shows an example of a standard broadband connection. I've just used the numbers there as examples too.

Sooo..if we imagine it's a standard ADSL connection with a download SPEED of 8Mbps, an upload SPEED of 1Mbps and a BANDWIDTH of 0.5mb..this allows 500kb packets of data to travel downloads at speeds up to 8mbps and the same packet to upload at speeds of 1mbps..

I think this is correct, please say if not!

In the second example I am using the same SPEEDS but have quadrupled the bandwidth just for example purposes, so now it's a 2mb bandwidth.. here's where I'm going out on a limb..

This second example SHOULD allow 4 x 500kb packets of data to travel in any direction SIMULTANEOUSLY at the max up/down speed, if you're following?

OK BREAK TIME, NEED TO COLLECT THOUGHTS

And continuing..

The way I've made this into an analogy is using roads/motorways; if we imagine that the download speed is the road speed limit for this example, and the bandwidth is the amount of lanes on said road.

So a speed limit of "70mph" or 8mbps is on a single lane, it means a single car/packet of data can travel at that speed consistently providing there is no other traffic in the way, if more cars/packets are introduced everything slows down.

If we had a 4 lane motor way (or 4x as much bandwidth) instead of just 1 with a 70mph/8mbps speed limit, this hypothetically means that 4 cars/packets can travel at 70mph without being constricted.. yes? I think?

Sooooooo, all in all.. this should mean that a dedicated EFM line with a wider bandwidth than previous broadband, it should be much more efficient and heavy usage from multiple users will affect internet speed less..

As I said, this is a minefield of a topic and I believe this is how it's supposed to work in basic terms, can anyone comment/fill in? It's never a concept I've ever really needed to understand or visualise.

Thanks guys!

Jamie
 
Sorry for slow reply! It was a question but with myself trying to talk it through, although it seems I have been mislead by the people I have asked about this thus far!

Could someone please explain why a 2mb converged, uncontended EFM circuit will be far superior to ASDL for hosting a small business's voip and internet access?

I think I have an idea of it now but I'd like some clarification if someone would be willing to assist? :)

Cheers!
 
Sin_Chase said:
I think you are very confused.

A 2Mb converged 1:1 contention EFM Circuit will be better for VOIP/Internet over ADSL for the SHEER fact it's synchronous Download/Upload and has 1:1 contention - No other reason.

Bigger Upload > Smaller Upload.
1:1 contention > 40:1 contention

That's it. Stop complicating it.

Converged/Aggregated links actually have some downsides over single link connectivity options. Especially WAN based ones for internet connectivity.

PERSONALLY I would take a 2Mbit single link connection over an aggregated link.

To really simplify things for you consider this:

A 10Mbit single link internet connection is NO different in terms of download speed potential to a link made up of 5 x 2Mbit links.
Click to expand...

I am very confused correct, perhaps even more so now but I'll try and follow! :)

EFM uses multiple connections that kinda combine to create the total yeah? So hypothetically you could have either:

1 x single link EFM with 1:1 contention @ 2mbits
4 x aggregated(?) EFM with 1:1 @ 0.5mbits each

Does that work or am I even more confused now? D:

This confusion is purely down to being told different things by different people in various partner companies, I wish I could wipe my mind clean and go from scratch
 
Bremen - I agree, I don't really need to know but it's one of those things where I feel more comfortable dealing with something when I have a full understanding of it. It's tricky to find a website/article that explains EFM without trying to sell the solution to me instead :P

Chris - The EFM connection is going to be hosted by Gamma, it has SLA's and assurance on the line (apparently) - it's supposed to be pretty fail safe, it's just all so confusing cause lots of people say it will support voip and internet fine, and others that say it may not :(
 
I've had a read through the wikipedia, but the people I was speaking to at that point contradicted it - also there are higher speeds available but that's when the cost starts to climb dramatically
 
This is the only EFM circuit, the others are fibre:

Bearer - EFM
Bandwidth - 2Mbit/s
Spare Bandwidth - 0Mbit/s
Internet Bandwidth - 1Mbit/s
No Channels - 7
Codec - G711
Monthly Circuit Rental - £182.00

It's for 6-8 pc users on office 365 and 8 or so phones with about 4-5 concurrent max
 
Sorry lack of replies, hadn't seen this thread for a while! I've been discussing an upgrade to a 4mbit/s EFM circuit over the 2mbit/s - do you guys think that's more respectable for the usage described earlier?
 
Caged - The location is actually in a virgin fibre area, but it's set back from the street in what was once an old builders yard, therefore fibre doesn't reach that far! This is the best pricing we've had - also nothing has been purchased as of yet

I don't know a whole lot about it, but by "splitting onto separate lines", I meant splitting the voip and standard internet onto separate ADSL lines, at the moment I'm looking at having them converged on the one EFM line, 3mb dedicated for internet and 1mb for VOIP.

s0ck - Pretty much, now the company is using almost purely cloud solutions, and now moving to voip, the internet is unreliable, unresponsive and sluggish - we need to sort a solution to allow cloud IT and voip smoothly. Not looking for incredible speeds for streaming etc, needs to handle office 365 (emails and sharepoint hosted) basic browsing and RDP to a hosted sage server + voip.

I understand from what you've put that EFM has a lot less things to interfere with it's QoS and a lot more points of failure?
 
Hey guys, fibre is a possibility in the area but it's very expensive. You mention about openreach etc not being able to fix it etc. "Apparently", because the EFM is going to be installed and assured by Gamma, there's SLA's in place because they own every part of the infrastructure, limiting downtime?
 
nutcase_1uk said:
It did us - 6 offices all running off 1 mobile each office. The irony is the provider insisted we should use them as our existing ISP wasn't reliable enough. 1-0 to our ISP so far!
Click to expand...

Haha! :) To be fair, if it's just a salesman saying that, they're just basing it on the statistics/marketing gumpf that they are told to say.

I used to sell VF One Net; "Never miss a call!", "Constantly Connecting", "99.9% up time".. etc. etc... the system must have crashed 6 times in the first few months of it being available, leaving me to feel like a right tw*t after quoting Vodafone - since then I've never sold a product I haven't tested the crap out of myself! :P
 
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