Networked Application Architecture
• Application Functions
o 1. Client application interface
o 2. Business logic (functionality)
o 3. Back-end database
• Application Architecture
o Networked applications are “distributed” across multiple “tiers of service” with
network connect points or application interfaces
o The application architecture defines how/where these connect points take place
o Some are standards-based, some are proprietary
o Common Networked Applications
• Electronic mail
o ◦Uses simple protocols & request-response design
o ◦Implementation architectures vary, 2-tier and 3-tier
• Web Services
o Uses HTTP for “transport” of web page elements & HTML for web page
• Voice-over IP
o Uses SIP for call management
o Uses codecs and P2P for message exchange
Email Content and Delivery
• E-Mail message format/content standards
o Message format/content standards define the structure of e-mail messages.
o RFC 822/2822, HTML, UNICODE, MIME are message format standards.
• E-Mail delivery standards.
o Application delivery/transport standards (SMTP, POP, IMAP) control how e-mail
clients and servers communicate.
o TCP and IP for reliable routing and transport of e-mail packets.
E-Mail Standards: SMTP