As landline to mobile calls represent a large share of total PSTN minutes, I wonder if or how I should improve my testing when accepting a new SIP trunk with an ITSP.
I can see 3 testing policies:
- Do not specifically test calls to mobiles and extrapolate landline test results to mobile results (if your trunk work OK for landline, it should also for mobile)
- Specifically test calls to your favorite mobile operator and extrapolate results to other mobile operators
- Specifically test calls to each mobile operator
Now, regarding testing tools, how can you automate sending or receiving calls on a mobile phone ?
A. Use an Asterisk with a couple of USB/GSM/LTE/whatever dongle (and chan_dongle) ?
B. Use LTE and VoLTE, supposing mobile operators support VoLTE, and testing results can be extrapolated to casual mobile calls (does using VoLTE help ?)
C. Through a GSM to SIP gateway
D. Something else
Concerning which tests I would focus on, when a mobile phone is involved:
a. caller presentation (is callerid correctly sent to mobile)
b. early media or ring back tones
c. call forwarding (when a mobile unconditionally forwards to a landline, is a Diversion/History-Info header relayed to transfer target ?)
What are your experiences and opinions about landline to mobile testing ?
Which are your policy, tools and specific tests ?