Anything In Anything (AYIYA) is a computer networking protocol for managing IP

tunneling protocol In computer networks, a tunneling protocol is a communication protocol which allows for the movement of data from one network to another. They can, for example, allow private network communications to be sent across a public network (such as the ...

s in use between separated

Internet Protocol The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. IP ...

networks. It is most often used to provide

IPv6 Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic ...

transit over an

IPv4 Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. ...

network link when

network address translation Network address translation (NAT) is a method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic Router (computing), routing device. The te ...

masquerades a private network with a single

IP address An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...

that may change frequently because of

DHCP The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a clie ...

provisioning by

Internet service provider An Internet service provider (ISP) is an organization that provides a myriad of services related to accessing, using, managing, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, no ...

Features

The protocol has the following features: (Internet draft) * Tunneling of networking protocols within another IP protocol * Network

security Security is protection from, or resilience against, potential harm (or other unwanted coercion). Beneficiaries (technically referents) of security may be persons and social groups, objects and institutions, ecosystems, or any other entity or ...

is provided by preventing tunneled packets from being spoofable or replayable * Transparent handling of

* The endpoint of at least one of the two tunnel endpoints should be able to change to provide mobility features.

Tunnel brokers

Many consumer networks are provisioned by

Internet service providers An Internet service provider (ISP) is an organization that provides a myriad of services related to accessing, using, managing, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non ...

using

(NAT) which precludes the usage of IP protocol 41 tunnels (

tunneled in IPv4 per either RFC 4213 or RFC 3056) unless they manually reconfigure their NAT setup. In some cases, this is impossible as the NAT cannot be configured to forward protocol 41 to a specific host. Cases, where multiple endpoints are behind the same NAT, when multiple NATs are used, or when the user has no control at all over the NAT setup, are also problematic. This situation limits the deployment of IPv6, which was meant to solve the problem of the disruption in end-to-end communications caused by NATs, which were created because of limited address space in the first place. This problem can be solved by tunneling the IPv6 packets over either

User Datagram Protocol In computer networking, the User Datagram Protocol (UDP) is one of the core communication protocols of the Internet protocol suite used to send messages (transported as datagrams in Network packet, packets) to other hosts on an Internet Protoco ...

(UDP),

Transmission Control Protocol The Transmission Control Protocol (TCP) is one of the main communications protocol, protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, th ...

(TCP) or the

Stream Control Transmission Protocol The Stream Control Transmission Protocol (SCTP) is a computer networking communications protocol in the transport layer of the Internet protocol suite. Originally intended for Signaling System 7 (SS7) message transport in telecommunication, the ...

(SCTP). Taking into consideration that multiple separate endpoints could be behind the same NAT or that the public endpoint receives a new IP address, there is a need to identify the endpoint that certain packets are coming from and endpoints need to be able to change e.g. source addresses of the transporting protocol on the fly while still being identifiable as the same endpoint. AYIYA is independent of the transport and payload's protocol. An example is IPv6-in-UDP-in-IPv4, which is a typical setup that can be used by IPv6 tunnel brokers.

Mobility

AYIYA may be used to provision mobile hosts by tunneling traffic from the home address to the home agent over an underlying network. Any remote host that the mobile host communicates with does not need AYIYA support. When the remote host does support AYIYA, it could also directly set up a tunnel with the mobile host. The remote host can determine whether a host supports AYIYA by querying for

Domain Name System The Domain Name System (DNS) is a hierarchical and distributed name service that provides a naming system for computers, services, and other resources on the Internet or other Internet Protocol (IP) networks. It associates various information ...

records and use

public-key cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...

to authenticate the packets.

+-------------+             +------------+         ,--------.         +-------------+
,  Mobile Host ,  <--AYIYA--> ,  Home Agent ,  <---->  <----> ,  Remote Host , 
+-------------+             +------------+         '--------'         +-------------+

Using AYIYA to provide IPv6 for a host already provides mobility for that endpoint as it can use its IPv6 address regardless of geographic location.

Packet format

For IPv6 over IPv4-UDP operation, the most common use scenario, the identity is the IPv6 Address of the endpoint (16 bytes) and the signature is an SHA1 hash (20 bytes). The header has a total of 8 + 16 + 20 = 44 bytes. Encapsulated in UDP and IPv4, the tunnel overhead is 44 + 8 + 20 = 72 bytes. Over Ethernet this allows an MTU of 1428 bytes.

Implementations

The AYIYA protocol has been implemented in AICCU.

References

{{reflist

External links

SixXS
Tunneling protocols IPv6 transition technologies