For SSH:
user@srx# set applications application my-ssh inactivity-timeout 3600
For JWeb:
user@host# set system services web-management session idle-timeout "minutes"
For Telnet:
I assume its something like
user@srx# set applications application junos-telnet inactivity-timeout 3600
To View Timeouts:
user@host> start shell user root
Password:
user@host% vty fwdd
BSD platform (OCTEON processor, 416MB memory, 8192KB flash)
FLOWD_OCTEON(srx240a.hk vty)# show usp app-def tcp
tcp port=0, appl_name=junos-tcp-any, service type=0, alg id=0, timeout=1800
tcp port=21, appl_name=junos-ftp, service type=1, alg id=1, timeout=1800
tcp port=22, appl_name=junos-ssh, service type=22, alg id=0, timeout=1800
tcp port=23, appl_name=junos-telnet, service type=10, alg id=0, timeout=1800
tcp port=25, appl_name=junos-smtp, service type=7, alg id=0, timeout=1800
tcp port=43, appl_name=junos-whois, service type=46, alg id=0, timeout=1800
tcp port=49, appl_name=junos-tacacs, service type=0, alg id=0, timeout=1800
tcp port=53, appl_name=junos-dns-tcp, service type=16, alg id=16, timeout=1800
tcp port=65, appl_name=junos-tacacs-ds, service type=0, alg id=0, timeout=1800
tcp port=70, appl_name=junos-gopher, service type=39, alg id=0, timeout=1800
tcp port=79, appl_name=junos-finger, service type=17, alg id=0, timeout=1800
tcp port=80, appl_name=junos-http, service type=6, alg id=0, timeout=1800
<snip>
The above is to check for TCP services.
You can read the inactivity timeout for all defined services.
E.g. junos-telnet is having inactivity timeout 1800s.