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New Member

bandwidth question..

we hv 512 kbps lease line from provider between our end & our retiler end.mrtg showing 300 kbps input & 360 kbps output . do we assume it going out of limit as 300+360 =660 kpbs as we r suffring udp packet loss as our server send 700 udp packet but client recives less then 300..!!!

how do i calculate free bandwidth & used one ?


Re: bandwidth question..

yes, you are having shortage of bandwidth.

Rx Traffic % = (300/512)*100 = 58% approx

Tx Traffic % = (360/512)*100 = 70% approx

Total BW Util = Rx+Tx= 128%

Hence your network is using more BW than what you have and hence you might see packet drops when link is heavily utilized.

hope it helps ... rate if it does ...

Re: bandwidth question..


If you have a 512Kbps link you have 512K on both the ways for both upload and download.

Since its normally a full duplex the total bandwidth is available to you assuming your SP hasn't applied any CAP at their end.


New Member

Re: bandwidth question..


Do u think thr any logic in sourab reply..! & plz elaborate what you want to say..

Re: bandwidth question..

Hi Sunil

I was trying to elaborate that you gotta 512K on both the ways and you are using 300K & 300+ K .Still you have few hundred Kbps of bandwidth left on your pipe.

Sourabh in his post has mentioned that your upload link utilization is 58% and download utilization is 78%.

Normally people chalk out a strategy for upgradation if the usage is consistently maintained at or more than 75%.

You need to go thru the reports which will be available to you from your MRTG server about the weekly/monthly utilization pattern based on which you can decide for upgradation.

Also if its normal point to point link connecting 2 of your locations you can make use of QOS to efficiently use the available bandwidth.


New Member

Re: bandwidth question..

ok , then what could be reason of udp packet loss, not reaching to clients, as we are using tuneel between both routers & tunnel's utilization goes 400 kbps at the peak time as server sends udp packet after each 14 minutes.Hardly hafl of udp packet reach to the client.It's a type of udp directed broadcast


Re: bandwidth question..

UDP traffic has no intrinsic pacing.

Whether your client is ready to receive or not, your transmitter is putting out the traffic.

If the receiver's buffer fills up and the transmitter is still sending, the traffic will be dropped.

When UDP is used, you need to either pace it from a higher level (like TFTP does), or you don't care (or there's no correction) that traffic gets dropped (like streaming video or VoIP).

When I say "don't care or no corrective action" think of a VoIP phone call ... if the receiver figures out that a packet has been dropped, there's no way to get another one sent and still maintain the correct sequence .... so, for VoIP, the receiver's CODEC "fills in" the missing packet(s) by "blending" the packets before and after the one(s) that were dropped.

If there's a bunch dropped, then the receiving ear will hear a click, pop, or distortion.

What application or test are you using?

Try it with several stations at one end talking to one station at the other, and use TCP-based applications.

If you have only one pair of endpoints, then use something like FileZilla FTP and tell it to transfer a directory of several files.

Filezilla will send multiple streams at once and can pretty much fill the pipe all by itself (and give pretty good stats).

Good Luck


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