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Tommix3

join:2001-06-02
Southington, OH

T1 and VOIP Connections

I want to check with you guys to see if I correctly understand what our service should look like compared to what it does.

Currently we have a T1 from a semi large vendor. We use that for VOIP and Internet data. We have Exchange but with only 19 people it isn't hammered. We have at the most, 8 people on the phone at the same time with about 3-4 the average.

Data is slow most the time. I can run a speed test and get 1.55 mbs but if I start a download, say any size over 50 meg, the speed will instantly drop to maybe 500 or 600 kbs. I can duplicate this over and over. I've worked with T1's before and a much larger network with more people. We don't have any significant data usage.

The Company tells me it is a bandwidth problem and that we should buy another T1 which seems like over kill to me.

Isn't a T1 supposed to provide constant 1.55 or is what I described normal. Please advise quickly.

Thank you for your time! Tom



tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9
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I'm a little confused by your post. If I understand correctly:

1) Running speed test by itself you get 1.55 Mbps. - but you say that is slow. What speed were you expecting over a 1.544 Mbps T1? I would have expected slightly slower report due to TCP/IP overhead.

2) If you do a download and run speed test at the same time speed test reports 600 kbps. That seems reasonable to me. Unless you are running some sort of QoS both the file transfer and speed test are statistically multiplexed over the T1. Exactly how they split is impossible to tell.

/tom



TeleServPro
Premium
join:2009-08-24
reply to Tommix3

If your T1 is also being used for VoIP calls that might explain why the data portion is slow at times.. Do you know how much bandwidth is being used for each call?

I concur with the other reply about overhead. It would surprise me that you're getting 1.55M on a speed test. Usually with overhead, it would be 1.4-something..

A T1, or any other bandwidth medium is not going to be constant when you're downloading a file. When it's being used, the speed drops during that period of time.

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Tommix3

join:2001-06-02
Southington, OH
reply to tschmidt

Re: T1 and VOIP Connections

Thank you for your reply.


Tommix3

join:2001-06-02
Southington, OH
reply to TeleServPro

Thank you

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Crypto_Bug

join:2001-05-31
Torrington, CT
reply to Tommix3

Re: T1 and VOIP Connections

How many concurrent calls is the T provisioned for? A T1 will typically support 24 concurrent calls if it is provisioned for just VOIP use. My guess is the bandwidth issues are due to other things. typically large file transfers want to suck up all available bandwidth which slows other things down. The VOIP is typically provisioned separately.
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