To enable ALG:
kmodule_ctl nf_conntrack_sip enable
kmodule_ctl nf_nat_sip enable
To disable ALG:
kmodule_ctl nf_conntrack_sip disable
kmodule_ctl nf_nat_sip disable
ALG is disabled on the default setting.
Note: SIP ALG setting is not saved to flash in the Vigor2130, so if you reboot the router, you will have to re-enter the commands again to re-enable SIP ALG
Update: SIP ALG can now be enabled/disabled using the GUI interface under NAT >> ALG