Embed Size (px)
DESCRIPTION
Chapter 3 TCP and IP 3 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
Citation preview
Chapter 3 TCP and IP1
Chapter 3Chapter 3TCP and IP
Chapter 3 TCP and IP2
Introduction Introduction Transmission Control Protocol (TCP)User Datagram Protocol (UDP)Internet Protocol (IP)IPv6
Chapter 3 TCP and IP3
TCPTCPRFC 793, RFC 1122Outgoing data is logically a stream of
octets from userStream broken into blocks of data, or
segmentsTCP accumulates octets from user until
segment is large enough, or data marked with PUSH flag
User can mark data as URGENT
Chapter 3 TCP and IP4
Similarly, incoming data is a stream of
octets presented to userData 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
Chapter 3 TCP and IP5
Checksum FieldChecksum FieldApplied to data segment and part of the
headerProtects against bit errors in user data and
addressing informationFilled in at sourceChecked at destination
Chapter 3 TCP and IP6
OptionsOptionsMaximum segment sizeWindow scale factorTimestamp
Chapter 3 TCP and IP7
Figure 2.1Figure 2.1
Chapter 3 TCP and IP8
UDPUDPRFC 768Connectionless, unreliableLess overheadSimply adds port addressing to IPChecksum is optional
Chapter 3 TCP and IP9
Appropriate Uses of UDPAppropriate Uses of UDPInward data collectionOutward data disseminationRequest-responseReal-time applications
Chapter 3 TCP and IP10
IPIPRFC 791Field 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)
Chapter 3 TCP and IP11
Figure 2.2Figure 2.2
Chapter 3 TCP and IP12
Figure 3.1Figure 3.1
Chapter 3 TCP and IP13
Fragmentation and ReassemblyFragmentation 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
Chapter 3 TCP and IP14
Figure 3.2Figure 3.2
Chapter 3 TCP and IP15
Type of Service TOS SubfieldType of Service TOS SubfieldSet by source systemRouters may ignore TOSRouter may respond to requested TOS
value through:– Route selection– Subnetwork service– Queuing discipline
Chapter 3 TCP and IP16
Table 3.1Table 3.1
Chapter 3 TCP and IP17
Type of Service Precedence Type of Service Precedence SubfieldSubfieldIndicates degree of urgency or priorityLike TOS subfield, may be ignored and
there are 3 approaches to respondingIntended to affect queuing discipline at
router– Queue service– Congestion control
Chapter 3 TCP and IP18
IPv4 OptionsIPv4 OptionsSecuritySource routingRoute recording timestamping
Chapter 3 TCP and IP19
IPv6IPv6Increase IP address from 32 bits to 128Accommodate higher network speeds, mix
of data streams (graphics, video, audio)Fixed size 40-octet header, followed by
optional extension headersLonger header but fewer fields (8 vs 12),
so routers should have less processing
Chapter 3 TCP and IP20
IPv6 HeaderIPv6 HeaderVersionTraffic classFlow labelPayload lengthNext headerHop limitSource addressDestination address
Chapter 3 TCP and IP21
IPv6 AddressesIPv6 Addresses128 bitsLonger addresses can have structure that
assists routing3 types:
– Unicast– Anycast– multicast
Chapter 3 TCP and IP22
Figure 3.3Figure 3.3
Chapter 3 TCP and IP23
Optional Extension HeadersOptional Extension HeadersHop-by-hop optionsRoutingFragmentAuthenticationEncapsulating security payloadDestination options
Chapter 3 TCP and IP24
Figure 3.4Figure 3.4
