ADSL2 congestion question

The Cush · 27-04-2015 09:53PM #1

bk wrote: »

However not all hope is lost of you. If they run fiber to your exchange for VDSL, that will at least improve backhaul congestion, specially if your exchange was one previously feed by wireless point to point connection.

SpaceTime wrote: »

In a lot of smaller rural exchanges, it's not lack of ADSL2+ equipment that's the bottle neck, it's their link to the core network that's the issue. They need modern high capacity, properly IP based fibre links added.

Two quotes from another thread, didn't want to drag the other one OT.

Our local exchange, ADSL2, VDSL (Phase 30, 2016), not on the core fibre network, microwave linked (1 antenna now, 3 antennas back when the Google Maps camera car was around).

My brother, approx. 4kms from the exchange, has Vodafone broadband. Daytime DL is about 6 Mbps but this drops to less than 2Mbps in the evening. OK for basic browsing but useless for anything else. Congestion I assume, but where, at the exchange or the backhaul?

Eircom's prequel Widget for his phone line

{"xbc":false,"xec":false,"xfc":false,"xrc":false,"inga":false,"ingb":false,"maxDSL":"10M_832K_RH","maxDSLServiceCode":"IPARROW","phone":"061-xxxxxx","validationType":"phone","completed":true,"partialAddresses":[],"isRedCustomer":false,"ina":false}

Stats from his modem, at that time the speed test was 5.88 Mbps/300 kbps (wired connection to the modem)

How do these figures look for a 4km ADSL2 connection?
Could these figures/congestion possibly improve when the exchange is VDSL enabled next year?
What sort of capacity can a microwave link from an exchange handle, is it suitable for VDSL?

ED E · 27-04-2015 10:02PM

Ìts the microwave link. Some of them are 150Mbps, some are 12Mbps. The odd one might be 400Mbps if its very close to the next hop (usually a hub exchange nearby). Those figures would be for the entire village. So say theres 200 lines, at 7Mb each, thats 1400Mbps of bandwidth from the DSLAM with 150Mbps to service it. And thats not accounting for the voice and control circuits.

Before that goes VDSL it'll go NGN, they'll run fibre into the exchange. At that point congestion will disappear and shorter lines will be able to go closer to 24Mbps while awaiting VDSL.

EDIT: Your brothers line could go up to 8 or 9 Mb, but no higher.

The Cush · 27-04-2015 10:42PM

ED E wrote: »

The odd one might be 400Mbps if its very close to the next hop (usually a hub exchange nearby).

The 2 nearest fibre core exchanges (in the general direction the antenna is pointing) don't have a microwave antenna so the link must be travelling quiet a distance. We are in the Tipperary Town eircom maintenance area and it's approx. 25km straight line distance, is this possible?

ED E wrote: »

Before that goes VDSL it'll go NGN, they'll run fibre into the exchange. At that point congestion will disappear and shorter lines will be able to go closer to 24Mbps while awaiting VDSL.

Before the local exchange was ADSL enabled back in 2010, KNN (IIRC) were working on underground cables towards Limerick city, not sure if it was anything to do with ADSL at the time. They were around again lately working on the same route installing a new manhole by the looks of it (cement mixer going).

ED E · 27-04-2015 10:59PM

Looks like they point south, though getting the exact heading is hard with streetview.

My guess is the hub is cappamore and NGN from there.

EDIT: Nope. Cappamore doesnt have a receiving dish. Guess its bouncing so, or going via a cellular point of presence.

The Cush · 27-04-2015 11:03PM

ED E wrote: »

Looks like they point south, though getting the exact heading is hard with streetview.

My guess is the hub is cappamore and NGN from there.

No microwave antenna on the Cappamore exchange, had a look today.

ED E · 27-04-2015 11:08PM

You were too quick for me there.

ISL has a dish but its facing just north of Caherconlish.

Wherever its linked too, its not obvious.

ItHurtsWhenIP · 28-04-2015 01:54PM

ED E wrote: »

EDIT: Your brothers line could go up to 8 or 9 Mb, but no higher.

Ed - just for clarity - his brother would get those speeds on ADSL, but would not stand a chance of getting eFibre @ 4KM - would that be correct?

ED E · 28-04-2015 02:11PM

Yeah, those line stats suggest a 8-9Mb Stable ADSL sync.

No VDSL unless theres a cab within 2km, but tbh I dont see eircom bothering with cabs in that area at all. The exchange itself ok, but there isnt the density for 200 port cabs.

ItHurtsWhenIP · 28-04-2015 04:46PM

ED E wrote: »

Yeah, those line stats suggest a 8-9Mb Stable ADSL sync.

No VDSL unless theres a cab within 2km, but tbh I dont see eircom bothering with cabs in that area at all. The exchange itself ok, but there isnt the density for 200 port cabs.

Yep - Most of the exchanges in this area (I'm a little bit north-east of these guys) are to get eVDSL as there is fibre currently run to them, however there is no ADSL/ADSL2+ in a lot of them. We're slated for eVDSL Jan-Jun 2016.

griffzinho · 14-05-2015 02:39PM

I would advise anyone experiencing congestion to contact the National Consumer Agency and make a complaint and also to contact COMREG in order to make a complaint there as well.

Customer service is not the answer.

BuzzG · 14-05-2015 10:12PM

In a similar boat except our exchange is only ADSL so off peak get over 6 mbps down with ping 40-50 ms but come the late afternoon takes a nose dive until well after mid night. Did a speed test there now getting 729 kbps down with ping of 156 ms. Line stats are ok as we are only 2k from the exchange.

Speed: 7168 kbps/384 kbps Line Attenuation(Down/Up): 27.5 dB/ 17.0 dB DSL Noise Margin: 13.5 dB/ 15.0 dB
but I do notice I'm getting some errors, this is after 4 days with the router connected.

near-end FEC error fast: 0
near-end FEC error interleaved: 6232
near-end CRC error fast: 0
near-end CRC error interleaved: 5
near-end HEC error fast: 0
near-end HEC error interleaved: 75
far-end FEC error fast: 0
far-end FEC error interleaved: 6
far-end CRC error fast: 0
far-end CRC error interleaved: 0
far-end HEC error fast: 0
far-end HEC error interleaved: 0

The drop to the house was cut last year by work done by a contractor we had in and I fixed it with gel crimp connectors and resealed the conduit but I'm wondering if the drop line to the house was damaged somewhere else along it's length ! Internal wiring is fine and the line in runs straight to the master socket to which the router is connected. Was gonna swop out the drop to the pole with external CAT5e myself as it needs to go down the conduit. eircom came and tested the line and said all is well but I have my doubts. Would welcome any advice. Apologies for the long winded post

ED E · 14-05-2015 10:25PM

6k in 4 days? You're fine.

DSL Noise Margin: 13.5 dB/ 15.0 dB

Sitting pretty.

Upgraded backhaul is all you need.

BuzzG · 14-05-2015 10:31PM

Cheers Ed E, reckon it's backhaul but still have my doubts about the cable that was damaged. Lot of FEC going on which has me wondering a bit. Know it's normal but that much since I posted a few mins ago ! Just normal surfing not streaming video or anything.

stats now
near-end FEC error fast: 0
near-end FEC error interleaved: 21821
near-end CRC error fast: 0
near-end CRC error interleaved: 5
near-end HEC error fast: 0
near-end HEC error interleaved: 75
far-end FEC error fast: 0
far-end FEC error interleaved: 6
far-end CRC error fast: 0
far-end CRC error interleaved: 0
far-end HEC error fast: 0
far-end HEC error interleaved: 0
ADSL uptime :4 days, 4:41, 39 secs
ADSL activetime :0 min, 12 secs

The Cush · 15-12-2015 09:11AM

I was in my brother's house last evening sorting out a new set homeplugs during which I asked him how his adsl connection has been recently (it's been really bad in the evenings over the previous months), down to 800kbps dl last evening on a 7.1 sync.

Reassuring him it should improve sometime next year once the local exchange is upgraded to fibre and the congestion is removed, during the conversation he mentioned he'd seen KN and eir vans working on the main road from the local village to Limerick city (Barrington's Bridge area) today.

Just checked the fibre rollout map and lo and behold our local exchange marker (MR01_E01 Murroe Co Limerick) has changed from blue to dark green - Fibre Build commenced - completion work is in progress (Estimated date for first Live Fibre Services is early/mid 2016). Very surprised our exchange is been upgraded before other local exchanges where the fibre backhaul has been installed for many years (Cappamore/Doon/Cappawhite).

Although we're 4km from the exchange, too far for efibre, the backhaul upgrade to fibre will be very welcome, no more congestion. Can see the local WISPs (Munster Broadband/Celtic Broadband) taking a hit once the exchange goes live.

MBSnr · 15-12-2015 09:26AM

ED E wrote: »

Upgraded backhaul is all you need.

I'm 2.5Km from a fibre enabled exchange running ADSL1. i still get slow down at peak times. Correct me if I'm wrong but I thought regardless of the backhaul being good, ADSL1/2 suffered contention issues anyhow? Wouldn't that possibly be the case in some instances with a backhaul upgrade making little difference?

ED E · 15-12-2015 09:51AM

Nope, there's no inherent congestion/contention as each user has their own carrier. What you have is say a rack of 240 lines averaging say 4Mb in a rural area but only 100Mb of backhaul to back that up. Thats a theoretical max of around 900Mb but only 100Mb to serve it, thus at peak you're f'cked. But put in a 1GB link there (and they'll probably put in several) and all congestion disappears as the link back to the core is bigger than the sum of the users its feeding.

Realistically they only need to hit something like 1/2 of the net bandwidth they sell as you'll never see near to 100% of residential DSL lines fully loaded at the same time, but when you're talking small rural exchanges the next step is a 10Gb fibre link.

ADSL2 congestion question

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