Internet Communications Using SIP : Delivering VoIP and Multimedia Services With Session Initiation Protocol {2Nd Ed.}

Figure 19.4 Call flow for voicemail 1 HTTP GET WEB CALLER CONTROLLER VOICEMAIL SERVER 3 200 OK 9 200 OK 5 INVITE 1 - Caller sele ...

Collecting DTMF Digits Figure 19.5 shows the basic call flows for the plain collecting of dual-tone multi-frequency digits, with ...

Figure 19.5 Call flow for collecting DTMF digits 1 INVITE CALLER CONTROLLER DTMF Collector CALLED 3 200 OK 5 INVITE 1 - The cont ...

The controller then initiates a re-INVITE(Message 11) to instruct the caller’s UA in the re-INVITEmessage where to direct the DT ...

Interactive Voice Response System State-of-the-art interactive voice (IVR) systems can be implemented with voice recognition and ...

Figure 19.6 Call flow example for interactive voice response service 1 INVITE CALLER CONTROLLER IVR SERVER 3 200 OK MEDIA 2 INVI ...

VoiceXML servers also have some telephony features, such as call transfer and disconnect, but these may not always be necessary ...

Figure 19.7 Call flows for a scheduled conference. 1 HTTP POST WEB A B SCHEDULER MIXER 3 INVITE 4 INVITE 1 - Web server informs ...

Summary IP telephony gateways decomposition using master/slave protocols such as MGCP, MEGCO, or H.248 require specific packages ...

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339 Peer-to-peer (P2P) networks are a more recent innovation on the Internet. As mentioned in Chapter 18, “Quality of Service fo ...

The history of P2P networks shows an interesting pattern of innovation on the Internet. Innovators develop extremely popular app ...

Figure 20.1 Example of an overlay network Peer-to-Peer Networks P2P networksshare the computing resources available in the netwo ...

Not all nodes at the edge must be equal in an overlay network. Some P2P networks use the so-called “supernodes” that have more p ...

In a DHT, the hash function is used to determine which part of the P2P over- lay network is responsible for a particular piece o ...

Characteristics of P2P Computing The importance of P2P computing can be better understood by looking at its characteristics: ■■ ...

A significant exposure specific to P2P is malicious peer nodes that could inject false routing information in the peer discover ...

Figure 20.3 Chord Ring Areas of applicability of Chord to SIP include a distributed location service [9], registration [17], DNS ...

Figure 20.4 Discovery and call routing in (a) the trapezoid model for CS SIP and (b) in the P2P SIP model using DHTs in an overl ...

P2P SIP Model The caller queries the DHT layer (step 1) in the overlay network to determine the location of the peer node for th ...