Now in its fourth edition, the ground-breaking Artech House bestseller SIP: Understanding the Session Initiation Protocol offers you the most comprehensive and current understanding of this revolutionary protocol for call signaling and IP Telephony. The fourth edition incorporates changes in SIP from the last five years with new chapters on internet threats and attacks, WebRTC and SIP, and substantial updates throughout. This cutting-edge book shows how SIP provides a highly-scalable and cost-effective way to offer new and exciting telecommunication feature sets, helping practitioners design "next generation" network and develop new applications and software stacks. Other key discussions include SIP as a key component in the Internet multimedia conferencing architecture, request and response messages, devices in a typical network, types of servers, SIP headers, comparisons with existing signaling protocols including H.323, related protocols SDP (Session Description Protocol) and RTP (Real-time Transport Protocol), and the future direction of SIP.

Henry Hunter Calvert died at his family house at Cannakale in 1880 a few months after escaping from the rioting in Alexandria where he was British consul. The consulate was sacked and his collections destroyed. He had however sent an annotated list of his Greek amphora stamps to the British Museum, presumably to Charles Newton, with whom he and his brother Frank had frequent correspondence. This list was forgotten until the present writer 'found' it in a box-file in the Department of Greek and Roman Antiquities (its title at the time). Henry Hunter Calvert's Collection of Amphora Stamps and that of Sidney Smith Saunders publicly presents that material.

Until the nineteenth century all time was local time. On foot or on horseback, it was impossible to travel fast enough to care that noon was a few minutes earlier or later from one town to the next. The invention of railways and telegraphs, however, created a newly interconnected world where suddenly the time differences between cities mattered. The Clocks Are Telling Lies is an exploration of why we tell time the way we do, demonstrating that organizing a new global time system was no simple task. Standard time, envisioned by railway engineers such as Sandford Fleming, clashed with universal time, promoted by astronomers. When both sides met in 1884 at the International Meridian Conference in Washington, DC, to debate the best way to organize time, disagreement abounded. If scientific and engineering experts could not agree, how would the public? Following some of the key players in the debate, Scott Johnston reveals how people dealt with the contradictions in global timekeeping in surprising ways - from zealots like Charles Piazzi Smyth, who campaigned for the Great Pyramid to serve as the prime meridian, to Maria Belville, who sold the time door to door in Victorian London, to Moraviantown and other Indigenous communities that used timekeeping to fight for autonomy. Drawing from a wide range of primary sources, The Clocks Are Telling Lies offers a thought-provoking narrative that centres people and politics, rather than technology, in the vibrant story of global time telling.