I would suggest picking up all three books as pdf. Mine are left open on my desktop all the time for reference Original 1.2 book Alternative endpoints 264 Skype and GSM endpoints 264 Skype with mod_skypopen 265 GSM with mod_gsmopen 266 TDM with OpenZAP and FreeTDM 267 Regards, Stephen HostBBB - Online Learning Solutions http://www.hostbbb.com <http://www.hostbbb.com/> 207 Technology Group Inc. 1-888-229-9756 skype: Stephen_Dame From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch-users-bounces@lists.freeswitch.org] On Behalf Of Jayanth Acharya Sent: Friday, August 30, 2013 11:26 AM To: FreeSWITCH Users Help Subject: [Freeswitch-users] Question about the latest FreeSWITCH book Can anyone having the book let me know if it has material on mod_gsmopen ? It doesn't seem to be a module that many people use, and not sure the book would cover all modules, but it is what I am very interested in. I am looking at the general architecture, design principles, configuration etc. Basically something, that is not there in the Wiki.