Granstream have been around almost as long as SIP has, and their offerings have never dissapointed, from low budget two line handsets right through to full screen android endpoints and everything in between. For corporate environments grandstream has a unified phonebook format that can be downloaded by each phone to bring local directory features as well as some models having access to LDAP and similar.
We developed a phonebook generation system that can suck phonebook data from a range of sources, de-duplicate, order and then build into a phonebook.xml file for the grandstream phones to download. A time of writing we can take contact information from vTiger, SugarCRM, Quickbooks, osTicket, Joomla, Wordpress, MantisBT and several other lesser known systems, but we can easily add new interfaces as required.
If you're considering Grandstream or have them already and would like your company phonebook shared between them all then we've got a solution for you. Contact us today for information.