Ethernet protocol allows two types of transmission TCP/IP or UDP. TCP/IP is used to establish a single connection between two devices. Using a broadcast protocol, only UDP has the ability to communicate simultaneously to multiple devices on a LAN. Because the vast majority of Caller ID applications are deployed in multi-user environments, UDP is the clear choice of data transmission, and therefore is used for all EL CallerID.com devices.

UDP information is transmitted via containerized packets. Each packet contains layers of headers, checksums, routing instructions, and the actual data. One UDP packet is transmitted from a Caller ID device each time an event occurs, such as Caller ID data on an incoming telephone call. Some CallerID.com products also monitor outbound telephone calls, in addition to, detailed information for every call. A separate UDP packet will be sent immediately for each event, and the data contained will strictly adhere to standard CallerID.com formatting.