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<a name="wp1072637"> </a><h1 class="pTitle">
Buffer Pools

</h1>
<a name="wp1072639"> </a><p class="pBody">
In the architecture of Generation 2, Generation 3, and Generation 4 modules, receive buffers shared by 
a set of ports are called <em class="cEmphasis">buffer</em> <em class="cEmphasis">groups</em>. The receive buffer groups are organized into <em class="cEmphasis">global</em> and <em class="cEmphasis">local</em> 
buffer pools. 

</p>
<a name="wp1072640"> </a><p class="pBody">
The receive buffers allocated from the global buffer pool to be shared by a port group are called a <em class="cEmphasis">global 
receive buffer pool</em>. Global receive buffer pools include the following buffer groups:

</p>
<div class="pSmartList1"><ul class="pSmartList1">
<a name="wp1072641"> </a><li class="pSmartList1">Reserved internal buffers 
</li>
<a name="wp1072642"> </a><li class="pSmartList1">Allocated BB_credit buffers for each Fibre Channel interface (user configured or assigned by 
default)
</li>
<a name="wp1072643"> </a><li class="pSmartList1">Common unallocated buffer pool for BB_credits, if any, to be used for additional BB_credits as 
needed
</li>
<a name="wp1072644"> </a><li class="pSmartList1">Performance buffers (only used on 12-port 4-Gbps and 4-port 10-Gbps switching modules)
</li>
</ul></div>
<a name="wp1118935"> </a><p class="pBody">


</p>
<a name="wp1072645"> </a><p class="pBodyAutonumNoRule">
<strong>Note	&nbsp;&nbsp;&nbsp;</strong> The 48-port and 24-port 8-Gbps modules have <em class="cEmphasis">dual</em> <em class="cEmphasis">global buffer pools</em>. Each buffer pool in the 48-port 
modules support 24 ports and in the 24-port modules each buffer pool supports 12 ports.

</p>
<a name="wp1098629"> </a><p class="pBodyAutonumNoRule">
<strong>Note	&nbsp;&nbsp;&nbsp;</strong> The default BB_credit buffer allocation is the same for all port speeds.

</p>
<hr /><br><p class="pBody">Copyright 2010-2013, Cisco Systems, Inc. All rights reserved.</p> 

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