pjsip.conf

[transport-udp]
type=transport
protocol=udp
bind=0.0.0.0
allow_reload=yes
external_media_address=172.217.25.78 // server ip address
external_signaling_address=172.217.25.78 // server ip address

pjsip_wizard.conf

[user_defaults](!)
type = wizard
endpoint/transport=transport-udp
endpoint/context=from-internal
endpoint/rtp_symmetric=yes
endpoint/rewrite_contact=yes
endpoint/force_rport=yes
endpoint/disallow=all
endpoint/allow=ulaw,gsm
aor/max_contacts=2
aor/qualify_frequency=30

[user1](user_defaults)
inbound_auth/username = 101
inbound_auth/password = password101

[user2](user_defaults)
inbound_auth/username = 102
inbound_auth/password = password102