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<p>Hallo Ramiro,</p>
<p><br></p>
<p>Freitag, 13. Juni 2008, meintest Du:</p>
<p><br></p>
<p><span class=rvts6><br></span></p>
<p><span class=rvts6>RAQ> By the way:</span></p>
<p><br></p>
<p><span class=rvts6>RAQ> a) How many hops a Flextronics 10U 144 Port Modular is doing?</span></p>
<p><br></p>
<p>3</p>
<p><br></p>
<p><span class=rvts6>RAQ> b) And the others?</span></p>
<p><br></p>
<p>3 too.</p>
<p><br></p>
<p><span class=rvts6>RAQ> c) How much latency am I loosing in each hop? (In the case of Voltaire</span></p>
<p><span class=rvts6>RAQ> switches: ISR 9024 - 24 Ports: 140 ns ; ISR 2004 - 96 ports: 420 ns</span></p>
<p><br></p>
<p>150 ns is the usual value - maybe it is just 140. As far as i know all the switch vendors use the samel 24-port silicon by Mellanox. Because of that you find the same number of switchports everywhere: 24, 144 and 288. 288 is the maximum number of ports you can get when you use a 24port silicon as basis and build a 3-HOP Fat-Tree. </p>
<p><br></p>
<p><span class=rvts6>RAQ> The alternatives are:</span></p>
<p><br></p>
<p><span class=rvts6>RAQ> a) Start with a good 24 port swith and grow up loosing latency and</span></p>
<p><span class=rvts6>RAQ> bandwidth</span></p>
<p><br></p>
<p>You can use the 24-port switches to create a full bisectional bandwidth network if you want that. Since all the big switches are based on the 24-port silicon this is no problem. </p>
<p><br></p>
<p><span class=rvts6>RAQ> c) Use the Flextronix 10U 144 Port Modular solution which will allow us</span></p>
<p><span class=rvts6>RAQ> to scale well in a couple years</span></p>
<p><br></p>
<p>But you have to pay now for an expansion that you might never get... Or want a fancy new network technology as soon as you upgrade.</p>
<p><br></p>
<p>Regards, Jan </p>
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