What does SIS stand for?
SIS stands for "Signalling Interworking Subsystem"
How to abbreviate "Signalling Interworking Subsystem"?
"Signalling Interworking Subsystem" can be abbreviated as SIS
What is the meaning of SIS abbreviation?
The meaning of SIS abbreviation is "Signalling Interworking Subsystem"
What does SIS mean?
SIS as abbreviation means "Signalling Interworking Subsystem"
