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This is a sub-selection from Latency...ugh


Telco_Tech

join:2009-05-18
Toledo, OH
reply to B52GUNR

Re: Latency...ugh

said by B52GUNR:

While it's a nice CYA maneuver by AT&T, I can't even imagine using VoiP with the latency over 3G (the best I've seen is 150ms). Still, I agree that users should be able to use their phone however they want and this is a good thing, again, even if it was a CYA.
I was wondering about that. How would Skype even be remotely usable over AT&T's network in its current state anyway? AT&T doesn't have to restrict apps to prevent them from eroding their profits - all they have to do is keep their network running poorly and then nobody will want to use VoIP via AT&T 3G. When the FCC comes knocking they can then say that they run a completely neutral network and that customers are free to use whatever apps they want.

- Tate

--
It's time to let go of TDM people. If it's not IP-based, it's crap!

megatron266
Premium
join:2007-08-11
Miami, FL

Come on guys let's be real here for a second. Latency is the delay in communication between two nodes on a network. When dealing with online gameing and data transfer this is an important factor. Computers have the capability to hold several conversations at once all dependant on hardware and bandwidth. When dealing with a voice conversation the lag is mostly dependant on how fast both people can reply to each other since in a normal human conversation only one person can talk at a time. A fraction of a second isn't going to make a difference if the people talking just snorted something good or took a really good downer. I just did a ping test with the furthest place possible (somewhere in WY) and the latency was 2500 milliseconds. A whopping 2.5 seconds of delay is not going to be noticed at all in a VoIP conversation.


bemis

join:2008-07-18
Reading, MA
Reviews:
·Comcast

said by megatron266:

A whopping 2.5 seconds of delay is not going to be noticed at all in a VoIP conversation.
Seriously?

I take it you have never experienced the joy that is a satellite linked international call? They freaking suck. You say something, then there's a 1-2 second pause before the other party hears it, then there's a 1-2 second delay before you hear their response.

That 2-4 seconds of delay is excruciating... unless you're practiced at handling the delays it can be very difficult to carry on a conversation normally.

megatron266
Premium
join:2007-08-11
Miami, FL

I see your point but still 2.5 seconds from the farthest server I found? I don't call out of the country. Most of my calls are within Florida. Calling PR or NYC is the farthest I call to reach family. Do we all live on the other side of the world from our families, friends, ect?

For the most part the wireless aspect of the call is from the phone to the tower. After that the data is on a physical line. AT&T would need to beef up its physical infrastructure where ever it can. But not everything is owned by AT&T either. AT&T can work on its own hardware. If the other person is in an area not serviced by AT&T then wouldn't the latency issue belong to that carrier? The same question could be said if the other person is not AT&T at all. What if they are Verizon or Sprint?


bemis

join:2008-07-18
Reading, MA
Reviews:
·Comcast

said by megatron266:

I see your point but still 2.5 seconds from the farthest server I found? I don't call out of the country. Most of my calls are within Florida. Calling PR or NYC is the farthest I call to reach family. Do we all live on the other side of the world from our families, friends, ect?

For the most part the wireless aspect of the call is from the phone to the tower. After that the data is on a physical line. AT&T would need to beef up its physical infrastructure where ever it can. But not everything is owned by AT&T either. AT&T can work on its own hardware. If the other person is in an area not serviced by AT&T then wouldn't the latency issue belong to that carrier? The same question could be said if the other person is not AT&T at all. What if they are Verizon or Sprint?
The latency we're talking about--250-500ms--is inherent to this type of wireless network, it's not actually about how far away you're calling, it's the fact that you're sharing spectrum with many others, and other factors that affect signal quality, error introduction, etc.

So the basic concept here is that in an ideal world AT&T, and other 3G providers, might be able to get their 3G latency to about 200ms average, which would be good, and VOIP would still be potentially lousy.

So this something that all carriers would currently be susceptible to--depending on density of users surrounding towers it may not even be possible to lower it to a tolerable level, think about NYC with it's massive buildings ... if you have a "tower" (really they are just antennas on buildings in NYC) in a particular area you might have thousands of potential users all within hundreds of feet of it. Even if you were to add more antennas you're only permitted/own a certain slice of spectrum that can be used. So you hit a point where there is a technical limit to what can be accomplished.

Someone who knows more about cell transceivers, signal propagation, etc can probably describe this better.

megatron266
Premium
join:2007-08-11
Miami, FL

No I think you explained it well. I see what you mean. Hmmm You have a point. So knowing this do you think any wireless carrier would be able to handle this type of traffic on a wireless network any time soon?


lastmile

join:2007-09-08
Robertsville, MO
reply to bemis

Glad this topic came up; what is all of the hub-bub if the VOIP quality is shoddy on 3G? Why not make a regular voice call and skip the delay...

I run pings over 3G all day to help keep the connection up and its typically around 400ms-600ms dependant upon load && traffic. 3G spikes go over 1500ms all the time.

Sometimes latency is 90-200ms for a period of time when traffic is low but when if there is delay exceeding that, I would think you may as well resort to the old CB or walkie-talkie..

"breaker breaker", "over", "over and out"...