Copyright 1999, S.D. Personick. All Rights Reserved. Telecommunications Networking II Lecture 35 Emerging Protocols Tanenbaum: pp

Copyright 1999, S.D. Personick. All Rights Reserved. Emerging Protocols : IPv6 The current version of the IP (layer 3) protocol is IPv4: -address space is limited by the use of 4- byte addresses, and by the way those addresses are assigned -lacks security functionality -inadequate flexibility to support new and differentiated network layer services

Copyright 1999, S.D. Personick. All Rights Reserved. Emerging Protocols : IPv6 IPv6 provides: -16 byte addresses (3.4 x 10 **38 possible addresses!!!) -Header simplification: 7 fields plus options vs. 13 for IPv4 -Better support for options; simplifies the job of routers -Authentication and privacy features -Better support for differentiated “types of services”

Copyright 1999, S.D. Personick. All Rights Reserved. IPv6 Header VersionPriority Flow label Payload LengthNext HeaderHop limit Source address: 16 bytes Destination Address: 16 bytes

Copyright 1999, S.D. Personick. All Rights Reserved. IPv6 Header Version: always 6 for IPv6 and 4 for IPv4 Priority field: distinguishes between packets that can be buffered/delayed vs. packets that must either be sent immediately or discarded (and in-between cases) Flow label: allows source-destination pairs to set up the equivalent of virtual circuits with may (for example) have defined quality-of-service specifications

Copyright 1999, S.D. Personick. All Rights Reserved. IPv6 Header Payload length: tells how many bytes follow the 40-byte header Next header: tells which (optional) “extension header” type (if any) follows this header. If this is the last header, indicates which transport protocol (TCP, UDP…) to pass this packet to Hop counter: decremented on each hop

Copyright 1999, S.D. Personick. All Rights Reserved. IPv6 Extension Header Types Hop-by-hop options extension header: miscellaneous information that every router must pay attention to; for example: - “jumbogram” : used to identify datagrams longer than 65,536 bytes Routing extension header: used to specify the route to be taken by a datagram

Copyright 1999, S.D. Personick. All Rights Reserved. IPv6 Extension Header Types Authentication extension header: verification of the sender’s identity-- used to embed a digital signature Encryption security payload extension header: used to managed encrypted payloads See “Controversies” pp of Tanenbaum

Copyright 1999, S.D. Personick. All Rights Reserved. Emerging Protocols: RSVP Used to describe bandwidth and/or quality- of-service requirements to the network (I.e., to the routers in the network, and their associated management entities) Does not specify or provide insights into how the network will arrange to actually deliver on these requests

Copyright 1999, S.D. Personick. All Rights Reserved. Emerging Protocols IP/Telephony Gateways: Protocols to support interoperability between the Internet and traditional telephony networks (“Internet telphony” applications) IPSec: Protocols to support secure communication using the Internet (or private Internets)