By default, ESP is selected in IVE OS 7.2r1.1, and JunosPulse Client 3 taks some time to failover from ESP to SSL Transport.
On the SSL VPN side, I forced to SSL and its perfectly working without any delay or without opening any extra port on the Firewall.
And is Tunnel is Over SSL.
Currently, I am using SSL Tunnel (layer 4) and not facing any performance issue. The advantage of using this SSL-Tunnel, No need to open any port on server (SSL-VPN) or client side.