|RSIP, Realm Specific IP|
|Protocol type:||Application layer protocol.|
|Ports:||4555 (TCP, UDP).|
|Links:||IANA: RSIP parameters.|
An alternative to a NAT is an architecture that allows the hosts within the first (e.g., private) routing realm to directly use addresses and other routing parameters from the second (e.g., public) routing realm. Thus, RSIP has been defined as a method for address sharing that exhibits more transparency than NAT. In particular, RSIP requires that an RSIP gateway (a router or gateway between the two realms) assign at least one address from the second routing realm, and perhaps some other resources, to each RSIP host. An RSIP host is a host in the first routing realm that needs to establish end-to-end connectivity to a host, entity or device in the second routing realm. Thus, the second routing realm is not directly accessible from the RSIP host, but this system allows packets to maintain their integrity from the RSIP host to their destination. ALGs are not required in the RSIP gateway. RSIP requires that hosts be modified so that they place some number of layer three, layer four or other values from those assigned by the RSIP gateway in each packet bound for the second routing realm.
The use of TCP as the transport protocol is mandatory.
UDP can be used as an optional transport.
|MAC header||IP header||TCP | UDP header||RSIP message|
RSIP header, version 1:
RSIP version number.
Specifies the message contained in the current packet. There may be only one message per packet.
The total number of bytes in the RSIP message including the three mandatory fields.
Message. Variable length.
Type. 8 bits.
|12||variable||Vendor Specific Parameter.|
Length. 8 bits.
Value. Variable length.
(RFC 3103). An association of some combination of a local address, one or more local ports, a remote address, and a remote port with an RSIP host.
(RFC 3103). A routing realm that uses private IP addresses from the ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) or addresses that are non-routable from the Internet.
(RFC 3103). A routing realm with unique network addresses assigned by the Internet Assigned Number Authority (IANA) or an equivalent address registry.
(RFC 3103). A general way to refer to an item that an RSIP host leases from an RSIP gateway; e.g., an address or port.
RSA-IP, Realm Specific Address IP.
(RFC 3103). An RSIP method in which each RSIP host is allocated a unique IP address from the public realm.
RSAP-IP, Realm Specific Address and Port IP.
(RFC 3103). An RSIP method in which each RSIP host is allocated an IP address (possibly shared with other RSIP hosts) and some number of per-address unique ports from the public realm.
(RFC 3103). An application program that performs the client portion of the RSIP client/server protocol. An RSIP client application MUST exist on all RSIP hosts, and MAY exist on RSIP gateways.
(RFC 3103). A router situated on the boundary between a private realm and a public realm and owns one or more public IP addresses. An RSIP gateway is responsible for public parameter management and assignment to RSIP hosts. An RSIP gateway may act as a NAT router for hosts within the private realm that are not RSIP enabled.
(RFC 3103) A host within the private realm that acquires publicly unique parameters from an RSIP gateway through the use of the RSIP client/server protocol.
(RFC 3103) An application program that performs the server portion of the RSIP client/server protocol. An RSIP server application MUST exist on all RSIP gateways.
[RFC 3102] Realm Specific IP: Framework.
[RFC 3103] Realm Specific IP: Protocol Specification.
[RFC 3104] RSIP Support for End-to-end IPsec.
[RFC 3105] Finding an RSIP Server with SLP.