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belgorod1968

join:2013-02-28
Sherman Oaks, CA

Slower download speed after switching from AT&T U-verse.

Good day everyone! 4 days ago I started a new Fusion Internet and Phone Service with DSLX. Previously, I had AT&T U-Verse 12Mb service and they delivered about 10M most of the time. So, with advertised speed of up to 20Mb from DSLX, I hoped to get at least 13-14Mb. Unfortunately, what I get now is no more than 8.6M, which is even slower than AT&T, although the upload speed did go up to about 1M. I wonder if there is anything I can do to increase the download speed of my internet connection.
Also, with Fusion I started to have this strange thing, that one particular site ( vk.com) doesn't load right, doesn't load pictures at all and looks weird, whereas all other dozens of sites that I visit load just fine. I tried to disable firewall and antivirus, but no luck. I also connected DSL modem ( Comtrend CT-5072T) straight to a computer and again it's not loading correctly. However, when I connect to my neighbour's wireless network this site loads just fine. So, I assume the problem comes from DSLX. Maybe they block something.
Thank you very much for your time and help!


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC
said by belgorod1968:

4 days ago I started a new Fusion Internet and Phone Service with DSLX. Previously, I had AT&T U-Verse 12Mb service and they delivered about 10M most of the time. So, with advertised speed of up to 20Mb from DSLX, I hoped to get at least 13-14Mb. Unfortunately, what I get now is no more than 8.6M, which is even slower than AT&T, although the upload speed did go up to about 1M. I wonder if there is anything I can do to increase the download speed of my internet connection.

AT&T U-verse Internet uses PTM, while Fusion uses ATM. The ATM circuit will incur an overhead of 15% while PTM does not. Figure {sync times 0.94} for a PTM circuit vs. {sync times 0.85} for an ATM circuit. For any given distance, IP-DSL (AT&T U-verse) will be a tad faster than straight ADSL2+/ATM.

Also, with Fusion I started to have this strange thing, that one particular site ( vk.com) doesn't load right, doesn't load pictures at all and looks weird ...

Are you using a browser with a blocking add-on? Although not DSLX, I do have Fusion (direct from Sonic.net), and that site loads fine for me.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum

belgorod1968

join:2013-02-28
Sherman Oaks, CA
Thank you for your answer NormanS! I'm using Google Chrome with no adblock. Plus, when I connect to a neighbor's network this site loads just fine. All this happens on all 3 computers and 2 tablets in my home and started when I switched to DSLX. Very strange. I have no idea what the reason can be.


TAZ

@qwest.net
Are you using PPPoE? This "things won't load / blackhole" issue sounds familiar - if the MTU of the PPPoE interface is 1492 (i.e. DSLX doesn't support/doesn't configure 1500 MTU on the PPPoE interface / RFC4638), the TCP MSS also needs to be clamped at 1452.

On my 20M ADSL2+ circuit, I get about 17M in TCP goodput (e.g. a speed test). That's taking into account both ATM and PPPoE overhead (1492 MTU on the PPPoE interface). I don't know how DSLX operates, but is it possible they only have one speed tier and will provision for the highest they determine the loop is capable of reliably operating at? If that's the case, it would explain why they advertise "up to 20M."


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC
said by TAZ :

On my 20M ADSL2+ circuit, I get about 17M in TCP goodput (e.g. a speed test). That's taking into account both ATM and PPPoE overhead (1492 MTU on the PPPoE interface). I don't know how DSLX operates, but is it possible they only have one speed tier and will provision for the highest they determine the loop is capable of reliably operating at? If that's the case, it would explain why they advertise "up to 20M."

DSLExtreme resells Fusion, which is a product of another CLEC: Sonic.net. Indeed, Fusion is a "one tier fits all" offering; but I doubt that DSLX uses PPPoE, because Sonic.net provides Fusion in DHCP only.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC
reply to belgorod1968
I can't guess what is going on with that site; maybe DNS? We wouldn't be using the seem DNS, despite that we are using essentially the same service.

WRT your speed issue, I'd like to revise my comment a little. While accurate regarding the ATM v. PTM circuits, I realize, on second thought, that your report of getting ~10 Mb/s on an AT&T 12 Mb/s tier is off. In my experience, if an AT&T circuit doesn't sync to with inverse 96%/85% (PTM/ATM) of speed, they won't offer the tier. A 12 Mb/s tier from AT&T should run at 11.5 Mb/s, not 10 Mb/s. Either there is a problem in the loop, or AT&T screwed up by putting you at a higher tier than they could support. You might ask the DSLX techs to look into it; if AT&T put you on the wrong tier, than your 8.5 Mb/s Fusion speed is probably as good as it will ever get. But if there is trouble in the loop which was shorting the AT&T tier, you could potentially get closer to 10 Mb/s from Fusion.

Keeping in mind the difference between PTM and ATM in the overhead effect. Fusion is designed to operate without tiers. The modem and DSLAM negotiate the most reliable connect speed for the circuit.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum


TAZ

@qwest.net
said by NormanS:

Keeping in mind the difference between PTM and ATM in the overhead effect. Fusion is designed to operate without tiers. The modem and DSLAM negotiate the most reliable connect speed for the circuit.

They don't quite negotiate the most reliable speed; they negotiate the highest rate while maintaining a certain target SNR. A quick search reveals that it's 9 dB by default on Fusion but can be lowered to 6 dB by calling. It's possible that some lines wouldn't be stable even at 9 dB and would need higher, while some lines would be OK going down to 6 or lower. (For example, I've run at 6 for a few years just fine.)

I should add here, that the customer can override the target SNR over telnet on at least some modems. (On some Broadcom-based modems, it's "adsl configure --snr 1"; replace "adsl" with "xdslctl" or "adslctl" on some modems.)

It may impact stability depending on the line quality, but it's easy to change to a higher number (and even go beyond the DSLAM suggested minimum). My experience with this so far: 20mbit at 2.9 dB SNR on an ADSL2+ circuit that previously only got 18mbit at 6 dB; running 24 hours now with no retrains or any large number of CRC errors (interleaving is on though, about 10ms delay)


dslx_steve
Premium,VIP
join:2011-03-24
Winnetka, CA
kudos:6
reply to belgorod1968
said by belgorod1968:

Unfortunately, what I get now is no more than 8.6M

With newly provisioned service, the DSLAM tends to start conservatively and then, over the first couple of weeks, ratchet the speed up. Currently, I see you set for about 9mbps down at 9.6db noise margin. I've tweaked the line manually and now I see you at about 20mbps at 6.6db. This should be stable. Let us know if you see any drops or problems on the connection.

Regarding your problem with getting to vk.com. This sounds like a DNS issue. I'm guessing that you have a router. The router is pulling from the default DNS server in your area but somehow not resolving to that particular site. You might want to temporarily change your DNS on your router (if you have one) or, if you don't have a router, on your computer. Try using an alternate DNS, something like Google's DNS (8.8.8.8 and 8.8.4.4) or OpenDNS's (208.67.222.222 and 208.67.220.220).

belgorod1968

join:2013-02-28
Sherman Oaks, CA
Thank you very much, Steve! You are a magician! Today my speed went up to almost 16M! I am so happy. Now I will try to resolve the issue with the site with my router. Thank you again!


dslx_steve
Premium,VIP
join:2011-03-24
Winnetka, CA
kudos:6
You're quite welcome. Enjoy!