Basis of the whole internet communication and because of that most important protocol, is the internet protocol. It was made in the year 1981 and is spread the widest by the version internet protocol version 4.

The SEVENSTAX IPv4 has the standard for the network layer of the OSI model and makes the addressing and the routing of data packets in the network. The SEVENSTAX IPv4 implementation contains following functions:

  • sending and receiving of IPv4-packets (RFC 791)

  • ready IPv4 lower-layer-protocol-API (für PPP/ Ethernet)

  • subnet mask with CIDR Blocks (Classless Inter-Domain Routing; RFC 1518 and RFC 1519)

  • IP-fragmentation after RFC 791 and reassembly after RFC 815

The IP fragmenting wins importance throughout the last years because of the Gigabit network. Furthermore the IP fragmenting is necessary for the sending and receiving of big UDP packets.

The SEVENSTAX IPv4-module is on the market in two different ways. The single device was made for the use in embedded systems with a network interface. The IPv4 supports a great number of network places and makes the basis for routing.

SEVENSTAX IPv4 - Single Device

The SEVENSTAX IPv4 single device is made for the use in classic Single Homed Hosts. Because of that every device has one IP address, a network mask and one gateway address. The parameters can be placed over extra protocols manual or automatic. IP address and networks will be checked on organization and date before being placed.

SEVENSTAX IPv4 - Multi Device

The SEVENSTAX IPv4 Multi Device can have an embedded system with several interfaces. All interfaces are independent and worth the same. The interfaces can be bound by one or more Ethernet interfaces and/or one or more PPP interfaces. Every interface has an IP address. The IP module also has a routing table, the IP address of the interfaces and the routing data are placed manually or by DHCP, Auto IP,PPP. IP addresses are checked for assignment and validation before being placed(see RFC 3330).

Network conflicts are sent on to the SEVENSTAX ICMP.

To suit the IPv4 specification the SEVENSTAX multi device IP modul does not carry packets from one interface to the next. That process is for the SEVENSTAX IP forwarding and the SEVENSTAX Twice NAT.