Andrew is right, the push affects different applications in various ways depending upon a couple variables:
- Traffic load
- Sensitivity of the service (VoIP vs. HTTP)
- Luck
I include luck because you'll push the policy 50 times and everything will be ok, and on the 51st time you'll completely trash the state table and people will be disconnected. They can reconnect immediately, but for the poor folks in customer service entering in line 50 on a complicated order in the ERP system it can be a maddening experience.