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AT&T Says Cable Operators Not Delivering Advertised Speed
Actually bought 150 users cable so they could test the network performance...
by Karl Bode 06:28PM Wednesday Feb 27 2008
AT&T's Group President John Stankey spoke at Merrill Lynch's Communications Forum today in New York, in the process taking a shot at cable broadband networks (webcast here). Stankey says that AT&T went into one of their cities, purchased cable broadband service for some 150 users (from the speed tiers cited, they appear to be Comcast connections), and then tested network performance.

The company poked and prodded the network for a period of several months. AT&T claims they found that peak downstream speeds were between 3-4Mbps, while average downstream speeds for the users ranged between 300kbps and 400kbps, significantly less than the advertised rate of six to eight megabits per second. Some Stankey comments we transcribed from the webcast (hat tip to IP Democracy):
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"What we tend to see folks talking about from a competitive perspective is obsessing on the local access speeds -- We like to talk about whether I get 6Mbps to the home with my service or I'm buying a 12Mbps service...(but)...the local access speed is not indicative of what the end performance is.

We went into a metro-area in one of our cities that we operate in, we pulled out over 150 different residential homes, we bought service from the MSO, we put probes on the network, and over the course of several months ran a series of tests and samplings on actual throughput and speeds...

The service we were buying here was a six or eight meg local access
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service...even at peak, these speeds were well below the advertised six our eight meg access speeds. Why? Because they're traversing other parts of the network that ultimately manage or throttle the throughput....the bottom line is access isn't enough.

AT&T certainly has a point that your connection speed depends on the entire path of the network, as well as local congestion and network management. That said, AT&T's fastest 10Mbps U-Verse tier is going to struggle to compete with Comcast DOCSIS 3.0 deployment when it comes to promised end throughput.

The FTTN architecture also pales in comparison to FTTH projects like FiOS, so obviously they're going to downplay advertised connection speed. AT&T made the decision to try and placate investors by spending less on initial deployments, though it remains very likely they'll ultimately embrace fiber to the home anyway.

Comcast's network management PR disaster and congestion could give AT&T a temporary edge, and AT&T is supposed to announce faster speeds (for users closer to the CO and via pair bonding) sometime this year. So cable users, given you've tested and tweaked your connections extensively, do you agree with AT&T's findings? Most of you seem to be getting what you pay for.

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Abingdon, MD

2 recommendations

For the critics/skeptics...

I have Comcast in Harford County, Maryland. I have the Blast! 16Mbps service. Here is a screen shot of downloading a 1.37GB CoD4 Demo file. I also included a tracert to the server from which I downloaded. I downloaded this same file, about the same time yesterday and saw the same results. I've downloaded Linux ISOs from good servers and see the exact same thing. The calculated 14Mbps average seems low to me, but whatever.

Las Vegas, NV

3 edits

2 recommendations


Comcast, with very few exceptions, has delivered speeds in excess of what they've advertised; here in the San Fran area.

Four years or so ago when they bought the AT&T network in this area and had to throttle down it was screwed for awhile but, since then, great.

Get the feeling that all these guys, cable/telco/wireless, are full of crap?