[nsp] I need ideas on how to simulate a 200ms round-trip latency and bandwidth limitation.

[Brian Vowell]

On the same topic...

Anyone have much experience with what Cisco calls Long Fat Networks 
(LFN)?  Specifically, I'm interested in the impact (if any) of 
implementing the "ip tcp window-size" command on a 1721 router.

We have several VSAT links overseas, and I'm thinking of pushing the ISP 
on the US side to implement this feature on their routers, but I want to 
be sure that it'll have an impact on performance.  The Cisco docs 
suggest setting the value to 750000, but don't go into much detail about 
how they arrive at that figure. 


--b

Goldberg Alain (IT) wrote:

>Thanks Brian,
>
>I need to conduct all the test localy here, as we want to see the
>behavior of rather heavy servers when they are not connected on the same
>LAN.
>Thank you anyway, I think I'll go for the 
>http://info.iet.unipi.it/~luigi/ip_dummynet/
>
>That was suggested.
>
>Thank you all.
>
>________________________________________________________________________
>________________________________________________________________________
>_________________
>Alain Goldberg - Network manager - CCDA/CCNA AGG-RIPE - Tower
>Semiconductors LTD.    Tel : 972-4-6506003 Fax : 972-4-6547788 Cell:
>972-64-209662
>________________________________________________________________________
>________________________________________________________________________
>_________________
>
>
>
>-----Original Message-----
>From: Brian Vowell [mailto:brian at digitalix.net] 
>Sent: Wednesday, June 02, 2004 11:25 AM
>To: Goldberg Alain (IT)
>Cc: cisco-nsp at puck.nether.net
>Subject: Re: [nsp] I need ideas on how to simulate a 200ms round-trip
>latency and bandwidth limitation.
>
>I have some routers at the other end of an 800ms link.  What kind of a
>test are you going to run?
>
>
>--b
>
>Goldberg Alain (IT) wrote:
>
>  
>
>>Hi all,
>>
>>I need to do some software tests between our main site and equipment
>>that will be collocated some 200ms from here.
>>I'd like to simulate the latency and some bandwidth limitation - let
>>    
>>
>say
>  
>
>>256Kbps.
>>
>>The testing equipment I have on-hands is:
>>A couple of 250x routers, ( I tough to put them with serials back to
>>back but can't find the Female V35 cable and it will not create the
>>desired latency anyway). 
>>A 2600 router with a couple of ethernets and one serial port.
>>An old 4500 router (enterprises image) . 
>>
>>A few 2924, 2950, 3550 switches
>>
>>A few 6500's  (enterprises image) that are in production - so I can't
>>play much with them - let say I can make changes on a specific
>>    
>>
>interface
>  
>
>>- but not global changes.
>>It has only ethernet ports.
>>
>>A VPN-3006, and a couple of VPN's 3002.
>>
>>A few AP-350's access points.
>>
>>Please guys ... Be creative.
>>
>>Thanks.
>>
>>_______________________________________________________________________
>>    
>>
>_
>  
>
>>_______________________________________________________________________
>>    
>>
>_
>  
>
>>_________________
>>Alain Goldberg - Network manager - CCDA/CCNA AGG-RIPE - Tower
>>Semiconductors LTD.    Tel : 972-4-6506003 Fax : 972-4-6547788 Cell:
>>972-64-209662
>>_______________________________________________________________________
>>    
>>
>_
>  
>
>>_______________________________________________________________________
>>    
>>
>_
>  
>
>>_________________
>>
>>
>>
>>_______________________________________________
>>cisco-nsp mailing list  cisco-nsp at puck.nether.net
>>https://puck.nether.net/mailman/listinfo/cisco-nsp
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>> 
>>
>>    
>>
>
>  
>