Planet XGS3-24042 User Manual download pdf (Page 195)

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every connection status which increases network delay greatly and decreases network performance.

Moreover, the translation of network data packet addresses baffles the end-to-end network security check,

IPSec authentication header is such an example.

Therefore, in order to solve all kinds of problems existing in IPv4 comprehensively, the next generation

Internet Protocol IPv6 designed by IETF has become the only feasible solution at present.

First of all, the 128 bits addressing scheme of IPv6 Protocol can guarantee to provide enough globally unique

IP addresses for global IP network nodes in the range of time and space. Moreover, besides increasing

address space, IPv6 also enhanced many other essential designs of IPv4.

Hierarchical addressing scheme facilitates Route Aggregation, effectively reduces route table entries and

enhances the efficiency and expansibility of routing and data packet processing.

The header design of IPv6 is more efficient compared with IPv4. It has less data fields and takes out header

checksum, thus expedites the processing speed of basic IPv6 header. In IPv6 header, fragment field can be

shown as an optional extended field, so that data packets fragmentation process won’t be done in router

forwarding process, and Path MTU Discovery Mechanism collaborates with data packet source which

enhances the processing efficiency of router.

Address automatic configuration and plug-and-play is supported. Large amounts of hosts can find network

routers easily by address automatic configuration function of IPv6 while obtaining a globally unique IPv6

address automatically as well which makes the devices using IPv6 Internet plug-and-play. Automatic address

configuration function also makes the readdressing of existing network easier and more convenient, and it is

more convenient for network operators to manage the transformation from one provider to another.

Support IPSec. IPSec is optional in IPv4, but required in IPv6 Protocol. IPv6 provides security extended

header, which provides end-to-end security services such as access control, confidentiality and data integrity,

consequently making the implement of encryption, validation and Virtual Private Network easier.

Enhance the support for Mobile IP and mobile calculating devices. The Mobile IP Protocol defined in IETF

standard makes mobile devices movable without cutting the existing connection, which is a network function

getting more and more important. Unlike IPv4, the mobility of IPv6 is from embedded automatic configuration

to get transmission address (Care-Of-Address); therefore it doesn’t need Foreign Agent. Furthermore, this

kind of binding process enables Correspondent Node communicate with Mobile Node directly, thereby avoids

the extra system cost caused by triangle routing choice required in IPv4.

Avoid the use of Network Address Translation. The purpose of the introduction of NAT mechanism is to share

and reuse same address space among different network segments. This mechanism mitigates the problem of

the shortage of IPv4 address temporally; meanwhile it adds the burden of address translation process for

network device and application. Since the address space of IPv6 has increased greatly, address translation

becomes unnecessary, thus the problems and system cost caused by NAT deployment are solved naturally.

Support extensively deployed Routing Protocol. IPv6 has kept and extended the supports for existing Internal

Gateway Protocols (IGP for short), and Exterior Gateway Protocols (EGP for short). For example, IPv6

Routing Protocol such as RIPng, OSPFv3, IS-ISv6 and MBGP4+, etc.

Multicast addresses increased and the support for multicast has enhanced. By dealing with IPv4 broadcast

functions such as Router Discovery and Router Query, IPv6 multicast has completely replaced IPv4

broadcast in the sense of function. Multicast not only saves network bandwidth, but enhances network

efficiency as well.

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Planet XGS3-24042 User Manual Page 195