Hello, Ava!
Have a good day!
Please attention:
U1911 can support the voice function but it cannot control the endpoint to make call/Drop call/Hold Call.
The following is its functions.
The unified gateway uses a highly-integrated SIP softswitch as the core and supports both narrowband and broadband services, helping effectively improve communication efficiency and reducing operating expenses (OPEX).
The unified gateway can connect to analog phones and IP phones at the same time.
Connect to local analog phones directly. (U1980 cannot directly connect to local analog phones.)
Use IP bearer networks to connect to analog phones through IADs.
Use IP bearer networks to connect to IP phones.
The unified gateway can connect to PSTN networks or dedicated network voice switches through digital, analog, and broadband SIP trunks.
I hope my answer can help you, thanks!