Hi, yes there are timers and retries that can be set, see below. However i'm not sure if that would fix it, check also you q.931 debugs, it is possible the disconnects comes from telco and not the gateway, 10 seconds while waiting 180 is not excessive.

sip-ua

timers ?

buffer-invite Time to buffer the INVITE while waiting for display info

connect Time to wait for confirmation a session connected

connection Connection related timers

disconnect Time to wait for confirmation a session disconnected

expires Time to wait for the expiration of an INVITE request

hold Time to wait during hold before disconnecting

info Time to wait before INFO retransmission

keepalive Options keepalive related timers

notify Time to wait before NOTIFY retransmission

prack Time to wait before starting PRACK retransmission

refer Time to wait before REFER retransmission

register Time to wait before REGISTER retransmission

rel1xx Time to wait before starting reliable 1xx retransmission

trying Time to wait for provisional response to INVITE

update Time to wait before starting UPDATE retransmission

retry ?

bye BYE retry value

cancel CANCEL retry value

info INFO retry value

invite INVITE retry value

keepalive KEEPALIVE retry value

notify NOTIFY retry value

prack PRACK retry value

refer REFER retry value

register REGISTER retry value

rel1xx Reliable 1xx response retry value

response Response Methods retry value

subscribe SUBSCRIBE retry value

update UPDATE retry value