Most modern PBXs implement call accounting interface using TCP/IP.
 
But there are situations in which the connection with the PBX must be made via serial cable (RS-232C) either because of the hotel's requirements or due to the PMS's requirements.
 
GuestCAS implements all methods of CDRs retrieval from PBX, among them:
	- Database
 
	- Email
 
	- FTP
 
	- HTTP
 
	- HTTPS
 
	- InfoBuffer360 Informatec
 
	- IP Socket
 
	- PBX proprietary protocols
 
	- Serial (RS-232C)
 
	- SFTP
 
	- SSH
 
	- Syslog
 
	- Telnet
 
	- TFTP
 
GuestCAS is compatible with the most relevant brands of PBXs used by hotels worldwide, such as: