Page Comparison

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https://www.juniper.net/documentation/en_US/junos/topics/topic-map/junos-software-license-features.html

S-SA-FP (Subscriber access feature pack)
S-SA-NK (Subscriber Access Feature Pack License Scaling Limit to NK Subscriber)
S-SA-4K/8K/16K/32K/64K/96K/128K/256K

Optional:

S-SSP-FP (Secure Policy feature pack license (intercept subscriber traffic securely)
S-SA-FP:     10 licenses are active when ordering the S-SA-FP