ndt-users list created

[Jeremy Palmer <>]

Can you clarify the definition of "sender" and "receiver"? It seems to me that
when the "client to server" test is running then the client is the sender and
the NDT box is the receiver but would be reversed when its running the "server
to client" test. Or am I looking at this the wrong way?

Rich Carlson wrote:
> Lize;
> 
> These are part of the Web100 triage values.  The web100 kernel maintains
> 3 possible states for a TCP connection.  These are sender limited (pkts
> can't leave the host because the sender's TCP window is closed - waiting
> for ACK's), receiver limited (the receiver's TCP window is closed -
> waiting for data to move up to the application), or network limited
> (either the Congestion window is limiting the flow, or no other limit is
> being hit).
> 
> As the NDT server streams data to the client the kernel records what
> state it was in when it stopped sending.  In this case 40% of the time
> the flow stops because the NDT server reached the max value for the TCP
> transmit window.  The other 60% of the time it was in the network
> limited state.  The More Details page will also include counters that
> tell you how many times the state changed.
> 
> This seems to indicate that you have not tuned the NDT server and it is
> becoming the bottleneck for the test.  I.E. the server can't send data
> faster because the TCP xmit window is too small.
> 
> What link speeds are you using?
> What is the server's CPU utilization?
> What are the TCP tuning parameters set to?
> 
> Rich
> 
> On 4/1/2010 5:53 AM, 
> 
>  wrote:
>> This connection is sender limited 39.55% of the time.
>> This connection is network limited 60.45% of the time.
>>
>> excuse me, i don't understand what does the two line above mean
>> could anyone explain for me?
>>
> 

-- 
Jeremy Palmer
Network Engineering
ViaWest, Inc.
Office: 720.891.1045
Fax: 303-874-5236
www.viawest.net