The SRX5K-SPC-4-15-320 Services Processing Card (SPC) contains four Services Processing Units (SPUs), which provide the processing power to run integrated services such as firewall, IPsec, and IDP (see Figure 1). All traffic traversing the services gateway is passed to an SPU to have services processing applied to it. Traffic is intelligently distributed by I/O cards (IOCs) to SPUs for services processing.
The services gateway must have at least one SPC installed. You can install additional SPCs to increase services processing capacity.