Lect1..ppt - 01/06/05 CDA 6505 Network Architecture and Client/Server Computing Lecture 3 TCP and IP by Zornitza Genova Prodanoff

ZGP002 Outline Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Internet Protocol (IP) IPv6

ZGP003 TCP RFC 793, RFC 1122 Outgoing data is logically a stream of octets from user Stream broken into blocks of data, or segments TCP accumulates octets from user until segment is large enough, or data marked with PUSH flag User can mark data as URGENT

ZGP004 TCP Similarly, incoming data is a stream of octets presented to user Data marked with PUSH flag triggers delivery of data to user, otherwise TCP decides when to deliver data Data marked with URGENT flag causes user to be signaled

ZGP005 TCP: Checksum Field Applied to data segment and part of the header Protects against bit errors in user data and addressing information Filled in at source Checked at destination

ZGP006 TCP: Options Maximum segment size Window scale factor Timestamp

ZGP007

ZGP008 UDP RFC 768 Connectionless, unreliable Less overhead Simply adds port addressing to IP Checksum is optional

ZGP009 UDP: Appropriate Uses Inward data collection Outward data dissemination Request-response Real-time applications

ZGP0010 IP RFC 791 Field highlights: –Type of service, defined in RFC 1349, see Figure 3.1 –More bit –Don’t fragment bit –Time to live (similar to a hop count)

ZGP0011

ZGP0012

ZGP0013 IP: Fragmentation and Reassembly Networks may have different maximum packet size Router may need to fragment datagrams before sending to next network Fragments may need further fragmenting in later networks Reassembly done only at final destination since fragments may take different routes

ZGP0014

ZGP0015 IP: Type of Service TOS Subfield Set by source system Routers may ignore TOS Router may respond to requested TOS value through: –Route selection –Subnetwork service –Queuing discipline

ZGP0017 IP: Type of Service Precedence Subfield Indicates degree of urgency or priority Like TOS subfield, may be ignored and there are 3 approaches to responding Intended to affect queuing discipline at router –Queue service –Congestion control

ZGP0018 IPv4 Options Security Source routing Route recording timestamping

ZGP0019 IPv6 Increase IP address from 32 bits to 128 Accommodate higher network speeds, mix of data streams (graphics, video, audio) Fixed size 40-octet header, followed by optional extension headers Longer header but fewer fields (8 vs 12), so routers should have less processing

ZGP0020 IPv6 Header Version Traffic class Flow label Payload length Next header Hop limit Source address Destination address

ZGP0021 IPv6 Addresses 128 bits Longer addresses can have structure that assists routing 3 types: –Unicast –Anycast –multicast

ZGP0023 IP: Optional Extension Headers Hop-by-hop options Routing Fragment Authentication Encapsulating security payload Destination options

ZGP0024