heidelberg, 11-12 may 1998 aims’99 workshop internet protocol version 6 (ipv6) Úna logan broadcom...

Heidelberg, 11-12 May 1998

AIMS’99 Workshop

Internet Protocol version 6 (IPv6)

Úna Logan

Broadcom Eireann Research Ltd.

http://www.broadcom.ie


AIMS’99 Workshop

Topics

• EURESCOM Project P803

• Why IPv6?

• Key IPv6 Features

• IPv6 Header

• Benefits of IPv6 over IPv4

• IPv6 Transition Mechanisms

• IPv6 Implementations & Deployment

• Conclusions


AIMS’99 Workshop

EURESCOM Project P803

• Development of European IP Testbed between partners to– Investigate IPv6– Investigate techniques for differentiated QoS in IP networks– Investigate different network architectures– Promote creation of European agreement, build relationships with Internet

standards bodies & industry

• IPv6 – Migration scenarios and Interworking

• Dual IP Layer, Tunneling, DNS, Compatibility– Protocol related IPv6 issues

• Mobility, Addressing, Security and Authentication, Routing, Traffic Flows and Multicast and Anycast


AIMS’99 Workshop

H1 R1 H2 R2

H3 R3 H4 R4

6Bone

P803 IPv6 Network

H3 R3 H4 R4

H = HostR = Router

R

RR

R

6Bone


AIMS’99 Workshop

Why IPv6 (1)?

• New version of the Internet Protocol

• Developed in the early ‘90s in the IETF

• Designed as an evolutionary step from IPv4

• Lack of Address Space was the driving force behind the new Internet Protocol


AIMS’99 Workshop

Why IPv6 (2)?

• Other kinds of markets will develop– Nomadic Personal Computing Devices – Networked Entertainment– Device Control

• IPv6 can provide the management and control needed– Common protocol that can work over a variety of networks– Large scale routing and addressing– Communicates with current generation of computers

• Meets today's requirements and the requirements of these emerging markets


AIMS’99 Workshop

Key IPv6 Features(1)

• Expanded Addressing Capabilities / Efficient Routing– IPv6 increases the IPv4’s address size from 32 bits to 128 bits – Address Autoconfiguration– Unicast, Anycast and Multicast Addresses– Hierarchical Addressing Structure

• Header Format Simplification– New streamlined header

• Improved Support for Options / Extensions– Allows efficient forwarding – Ability to add new options in the future


AIMS’99 Workshop

Key IPv6 Features(2)

• Flow Labeling Capability– Labeling of packets belonging to particular traffic "flows" for which the

sender requests special handling

• Mobility– Built in Route Optimisation

• Security– Authentication and Encryption.


AIMS’99 Workshop

IPv6 Packet Header Format

• Ver : Version number

• TC : (Traffic Class)Identify different classes or priority

• Flow Label : Request for special handling by routers within a network

• Payload Length : Length of the remainder of the packet following the IPv6 header

• Next Header : Type of header following the IPv6 header

• Hop Limit : Limitation for the impact

of routing loops

SourceAddress

Destination Address

Ver TC Flow Label

Payload Length Next Header Hop Limit

32 bits


AIMS’99 Workshop

IPv6 Flow Label

TC Flow Label

•Differentiated Services : Flow Label Field

–Used by hosts to label packets that

require special handling by routers

•Handling can be conveyed to routers–By a control protocol, e.g... RSVP–By information within the flow's packets themselves

•Integrated Services : Traffic Class

–Enables a source to identify the desired delivery priority of its packets, relative to

other packets from the same source •The Priority values are divided into two ranges

–Traffic that "backs off" in response to congestion, such as TCP traffic–Traffic that does not back off in response to congestion, e.g..., "real-time" traffic


AIMS’99 Workshop

Specialised Extension Headers

• Location– Between the IPv6 header

and before the upper layer headers in a packet

• Efficient – Most not examined or

processed until the packet reaches it’s destination

• Optional

Routing

Hop-by-Hop Options

Destination Options

Fragment

Authen-tication

Destination Options

Encapsulating Sec Payload

IPv6 Header Extension Headers Upper Layers


AIMS’99 Workshop

Packet Size and Fragmentation

• High packet latency hinders audio and video streams

• Fragmentation is a major source of high latency under IPv4

• IPv4 provides fragmentation at any point in the path – Routers along the path a packet travels perform fragmentation by so that

fragments are at most the size of next-hop link MTU

• IPv6 provides end-to end fragmentation – A source alone performs fragmentation by using a path MTU discovery

algorithm

• Fragmentation field has moved to an extension header


AIMS’99 Workshop

Voice over IPv6

• Problems with voice over IP today– Limited bandwidth– Also, in an Internet connection, the bandwidth can be very inconsistent – Latency – Unpredictable latency times

• Improvements for voice over IPv6– Limited bandwidth is not a protocol issue– More efficient routing system – More Efficient End-to-End fragmentation will improve latency– Still unpredictable latency times!


AIMS’99 Workshop

Benefits of IPv6 over IPv4 (1)

• Addressing scheme– IPv4’s workarounds (e.g.. DHCP and NAT, CIDR) only delay the inevitable!– Address Autoconfiguration reduces set up costs and provides easy

renumbering of sites

• Efficient Routing– Lack of uniformity in IPv4’s hierarchical system, limited addresses…

=> reduces performance, increases routing complexity and requires more routing information in backbone routers

– IPv6’s large hierarchical address space allows efficient routing.

• Simplified Reworked Packet Structure – Extension headers can be worked in as needed– With IPv6, most options are stored in the Extension headers, reducing

processing time at each hop.


AIMS’99 Workshop

Benefits of IPv6 over IPv4 (2)

• Improved Support for Mobility– Built in Route Optimisation

• Direct routing to a mobile node

• QoS– Improved Flow Handling efficiency

• Security– Built-in, Mandatory Security

Home Node

Sender Mobile Node

IPv4 IPv4

IPv6


AIMS’99 Workshop

6Bone

Correspondent Router Home Agent Router Node

Home Agent Router

P803 Mobility


AIMS’99 Workshop

IPv6 Implementations

• Over 50 IPv6 implementations completed or underway worldwide

• Host Implementations– Apple, Digital UNIX, FreeBSD, Linux, Microsoft, Solaris 2 (Sun), VMS

(DEC)…

• Router Implementations– 3Com, Bay Networks, Cisco Systems, Digital, IBM, Ipsilon, Telebit...


AIMS’99 Workshop

The Transition to IPv6 (1)

• The Transition Features– Incremental upgrade and deployment– Minimal upgrade dependencies – Low start-up costs– Easy Addressing

• The Transition Mechanisms– Dual IP layer technique – Addressing structures that embed IPv4 addresses within IPv6 addresses– Tunnelling IPv6 packets over IPv4 routing infrastructures

• Encapsulates IPv6 packets in IPv4 packets

Data Data

Transport Layer Transport LayerHeader decaps. Header

IPv6 IPv6Header encaps. Header

IPv4 Header


AIMS’99 Workshop

The Transition to IPv6 (2)

– Network Address Translation-Protocol Translation (NAT-PT)• Allows IPv6-only nodes to interoperate with IPv4-only nodes

• IPv6 DNS– IETF designers have defined DNS Extensions to Support IPv6

– Creates a new 128-bit DNS record type that will map domain names to an IPv6 address

– Reverse lookups based on 128-bit addresses are also defined

• Application Modification for IPv6– No direct access to the network stack - requires no updating to run in

the dual-stack environment – Directly interfacing with IP and related components - requires updating – Directly interfacing with both IPv4 and IPv6 - requires more extensive

updating


AIMS’99 Workshop

The 6Bone

• Launched in July 1996 • Virtual network

– Layered on top of portions of the physical IPv4-based Internet to support routing of IPv6 packets

• Test network– Allows the IPv6 protocol features and interoperability to be fully tested

• Currently, there 41 countries on the 6Bone

• Other similar initiatives– Internet2 (http://www.Internet2.edu/)– The Wide Project (http://www.v6.wide.ad.jp/)


AIMS’99 Workshop

Conclusions

• Sooner or later the address space will run out!

• IPv6 Deployment– Only experimental

– Vendors appear committed to the development of IPv6 – The core set of IPv6 protocols due to be fully standardised this

year

• Most IPv6 functionality has been retro-fitted into IPv4

• No substitute to a protocol designed from the ground up with scaleable addressing, advanced routing, security, QoS and related features

• IPv6 provides the platform for new Internet functionality needed in the near future


AIMS’99 Workshop

Additional Information

• http://www.playground.sun.com/pub/html/ipng-main.html– Pointers to current Specifications and implementations updated on a

regular basis

• http://www.ietf.org/– Information on the IETF organisation, Internet Standards, Drafts and RFC s

• http://www.eurescom.de/– Information on the P803 European IP Testbed

• http://www.6bone.net/– Information about the 6Bone and what you need to know in order to

participate

heidelberg, 11-12 may 1998 aims’99 workshop internet protocol version 6 (ipv6) Úna logan broadcom...

Documents

ipv6 header hop limit

bone slide

anycast slide

new internet protocol

future slide

type of header

priority flow label

flow label field