Describes the development history and status quo of router standards in an all-round way.

The routing technology must also comply with the router standard in its application. Although the current router standard is not complete yet, it is believed that with the development of routing, it will also be more improved and stable. Vro supports multiple protocols, such as TCP/IP, IPX, SPX, and AppleTalk. Even the TCP/IP protocol has versions 4 and 6. However, due to the fact that TCP/IP has become a standard, IPv4 occupies an absolute advantage in the network, so the router standard focuses on the specification to support IPv4 devices. IPv6 has its inherent advantages and may be widely used in the future. Therefore, we recommend that the standard router support IPv6, but it is not standardized.

In addition to the routers described in the standard, there are embedded routers and transparent routers. An embedded router is a computer system that provides the operating system function in addition to the routing function. Due to its inherent defects, it is not recommended to use the standard. A transparent router, also known as a shared-address router, is not standardized in the standard, but is not excluded from use.

Router standards are a specification that must be observed by routers working in a complex and diverse Internet. Although the current vro does not fully comply with the standards, gradually complying with the vro standards is an effort. Due to the complexity of the Internet and the diversity of actual situations, the current router standards should be recommended.

Router standard content

There are some differences between the low-end router standard and the high-end router standard content. The differences are mainly reflected in the router interface type, performance requirements, and reliability requirements. High-end routers have high performance requirements, high interface speed requirements, and high reliability requirements. They are mainly used for high-speed forwarding. Low-end routers require many functions, except for enterprise network applications, it is generally used for access in the public network. The two types of routers have little difference in basic functions. The following describes the main content of the router standard with a low-end router as an example.

The first part specifies the scope of the standard application and specifies the technical requirements of the router, including functions, indicators, communication interfaces, communication protocols, and environmental requirements.

The second part lists the router standards and specifications referenced by the router standards. As described above, there are nearly a hundred documents.

The third part lists all the definitions, terms, and abbreviations used in the router standards, mainly defining routers and low-end routers.

The fourth part points out the functions and implementation methods of the vro. They are as follows.

1) interface function: used to connect a router to a network. It can be divided into two types: LAN interface and WAN interface. LAN interfaces mainly include Ethernet, card ring, Token Bus, FDDI and other network interfaces. Wan interfaces include E1/T1, E3/T3, DS3, and common serial ports that can be switched to X.21DTE/DCE, V.35DTE/DCE, RS232DTE/DCE, RS449DTE/DCE, and EIA530DTE.

2) communication protocol function: This function is used to process communication protocols, including TCP/IP, PPP, X.25, and frame relay.

3) data packet forwarding function: this function is mainly responsible for forwarding data packets between ports including logical ports according to the content of the route table and rewriting the data packet header information at the link layer.

4) routing information maintenance function: This function runs the routing protocol and maintains the route table. The routing protocols include RIP, OSPF, and BGP.

5) Management Control: vro management control includes five features: SNMP proxy, Telnet server, local management, remote monitoring, and RMON. Control and Manage vrouters in five different ways and allow logging.

6) security function: This function is used to complete data packet filtering, address conversion, access control, data encryption, firewall, and address allocation. The basic functions that the vro must implement are also described in section 4.

Part 5 defines the physical layer specification of the router interface, including the E1 interface, ISDN interface, Ethernet interface, serial synchronous port, FDDI interface, and other interfaces. All of the above interface specifications reference existing standards and are not described in detail.

Part 6 describes the link layer specification of a router interface by referencing other standard specifications, including the serial link layer protocol, the frame relay Port Link Layer Protocol, the X.25 link layer protocol, and the ISDN link layer protocol. In addition, it also includes additional requirements on the Link Layer of the router: Address Resolution Protocol-ARP, coexistence of Ethernet and 802.3, maximum transmission unit-MTU, Point-to-Point Protocol-PPP, and interface testing.

Part 7 defines the Internet layer protocol of the router, including the IP protocol, ICMP protocol, and IGMP protocol. Vro's implementation of the preceding protocols is not a simple reference or translation, but a special provision made by vro devices on the options of the preceding three protocols. It is one of the important contents of the router standard.

Part 8 defines the basic functions and forwarding of routers. Specifically, the packet forwarding process complies with the Internet layer protocol STD5 RFC791, STD5 RFC950, STD5 RFC792, and RFC1016 ). This part of content mainly refers to RFC1812. According to the above several RFC documents, this is an important part of the router standard.

Part 9 specifies the transport layer protocol, including TCP and UDP. The router works on the IP layer, and there is no need to implement the transport layer protocol, but due to the need for Telnet for operation and maintenance) and the routing protocol, the router usually implements the above transport layer protocol. The description of TCP and UDP protocols is mainly used in simple applications. Only a few of the options are defined.

Part 10 describes the most complex protocol running on a vro by referencing other protocols: the routing protocol. It consists of two parts: internal routing and external routing. The internal gateway protocol is used to distribute routing information inside the AS, that is, AS internal routing ). The external gateway protocol is used to exchange routing information between AS instances ).

Part 1 describes the vro network management regulations. The required vro must support the SNMP v2 and the corresponding router standard MIB defined in RFC1902 to RFC1906.

Part 1 stipulates other application protocols. For all other application layer protocols implemented by routers, the routers must comply with the related requirements in STD3 and RFC1123.

Part 1 describes the vro operation and maintenance regulations. It mainly defines the content of router operation and maintenance, the specific provisions on router initialization, operation and maintenance, and the consideration of router security.

Part 1 describes the vro technical indicators. It mainly includes the packet loss rate, router throughput, router latency, router Authentication Technical Indicators, route table capacity, number of back-to-back frames, and its billing, synchronization, and Reliability Indicators. Finally, the support for AppleTalk and Novell protocol routers is stipulated, and the router environment requirements and power supply and grounding requirements are also stipulated.