Abstract: Systems and methods for establishing a communications channel between a first user and a second user through a first communications system make use of contact information obtained from a second communications system. The contact information obtained from the second communications system is stored in a cross-reference database maintained on the first communications system. The information could be obtained by having the first communications system access the second communications system using the credentials of a user of the second communications system to obtain contact information stored on the second communications system for the user. The information in the cross-reference database allows the first communications system to determine a non-publically switched telephony network (PSTN) identifier of a telephony device associated with the second user. This identifier is then used to establish a communications channel between the first user and the second user.

Abstract: A IP telephony service allows customers to form user groups. Each user group can include multiple telephony devices that are associated with one or more users. One or more group identifiers would be associated with each user group. When an incoming communication is directed to a user group, a group identifier is used to retrieve a list of the members of the group, or a list of devices that correspond to the members of the user group. The communication is then sent to one or more members of the group, or to one or more of the devices that correspond to members of the user group. Handling preferences may determine how the incoming communication is delivered. In some instances, the incoming communication could be a telephone call. In other instances, the incoming communication could be a SMS message or an instant message.

Abstract: A IP telephony service allows customers to form user groups. A user group is established by collecting a plurality of identifiers that are associated with members of a group, and associating the member identifiers with a group identifier. The member identifiers could be telephone numbers of telephony devices for each of the members, or device IDs of IP telephony devices for members of the group. The group identifier could be any type of identifier, and in some instances, the group identifier could be a telephone number.

Abstract: A IP telephony service allows customers to form user groups. Each user group can include multiple telephony devices that are associated with one or more users. One or more group identifiers would be associated with each user group. When an incoming communication is directed to a user group, a group identifier is used to retrieve a list of the members of the group, or a list of devices that correspond to the members of the user group. The communication is then sent to one or more members of the group, or to one or more of the devices that correspond to members of the user group. Handling preferences may determine how the incoming communication is delivered. In some instances, the incoming communication could be a telephone call. In other instances, the incoming communication could be a SMS message or an instant message.