As of January 2008, the world population was estimated to be 6.6 billion and is projected to reach 9 billion by 2050. As our population expands and becomes more technologically advanced, more people will use and be connected through the Internet, cell phones and other devices. Why does this matter? The growth of our population and use of networked devices means better and more scalable networks are needed to handle the increased bandwidth of users.
Version 4 of the Internet Protocol, more commonly called IPv4, is the most widely used version of Internet Protocol and is a set of techniques used to connect and transmit data over the Internet. IPv4 was designed in the 1970s by a U.S. government organization that wanted new, lower-layer protocols because the existing layers had become functionally inadequate. Since IPv4 was published in 1981, IP has enabled significant development and greater communication worldwide; however, the growth of Internet use has slowly taken its toll on IPv4.
Computers and devices that need to connect through the Internet require IP addresses. As more people connect, the number of IP addresses left dwindle. Reports estimate that the pool of unallocated IP addresses will run out by 2010, which is why experts started developing a new version of the Internet, called “version 6,” or IPv6, back in the 1990s. During this time, two problems became apparent; IP addresses were being exhausted and IP routing tables were growing very large. In theory, IPv4 is supposed to handle four billion devices, however, the practical limit based on current usage is more like 250 million devices. From 1991 to 1995, routing tables doubled in size every 10 months, which put additional stress on router processing power and memory allocation. The short-term solution was small changes to the current IP, including a new allocation policy and private IP addresses set aside for intranets. The long-term solution was a new IP version with much bigger address space.
Over the last two decades, the world has experienced an explosion of new Internet appliances — from IP phones and laptops to devices like network cameras. All of these devices need IP addresses. Reports estimate 1.5 billion Internet appliances by 2010 compared with 44 million in 2003. That is a significant increase in seven years. Internet usage has also seen strong growth. In 2007, an estimated 1.2 billion were using the Internet with the world total penetration rate at just under 17 percent. American Registry for Internet Numbers (ARIN), the regional registry of IP and ASN numbers for North America, South America, the Caribbean and sub-Saharan Africa, has made it clear that the limited number of addresses currently available means the migration to IPv6 is necessary.
Why IPv6?
IPv6 helps solve the IP address shortage because it supports 340 trillion trillion trillion unique addresses whereas IPv4 only supports four billion. In addition to more IP addresses, IPv6 brings superior reliability, flexibility and security to the Internet that IPv4 cannot provide. IPv4 has many issues that make it unviable for the future. For example, IPv4 was never designed to be secure. It was originally designed for an isolated military network and was later adopted as a public education and research network. IPv4 security is retrofitted, and many security features are optional — you cannot count on their availability. As technology advances, new applications are much more demanding on the network. They demand guaranteed on-time delivery, availability of bandwidth and increased security. The possibility of adding on to the base of IPv4 technology is costly, labor intensive and error-prone, which is why IPv6 is the way of the future.
IPv6 will not change the functionality of network video products, but it will make systems run more efficiently. Consider how people used to get mail. Decades ago, people were sent mail based on their name and street address. When the population grew, a zipcode system was designed so that the delivery of mail could scale to the increased number of people getting mail. Similarly, IPv6 is simply a more efficient way of delivering information.
In addition to the availability of IP addresses, the advantages of IPv6 include better IP address architecture, IP auto-configuration, renumbering to simplify switching entire corporate networks between providers, faster routing, point-to-point encryption and connectivity using the same address in changing networks.
IPv6 improves address architecture and simplifies how the address is represented. IPv6 addresses have a length of 128 bits and are written in hexadecimal notations consisting of eight double-bytes separated by colons. For example, an IPv6 address looks like 2001:0da8:65b4:05d3:1315:7c1f:0461:7847. To shorten the addresses, a number of consecutive zeroes may be abbreviated to a double colon, which is allowed once in any single IPv6 address. The address 2002:0da8::1315:7c7a is equivalent to 2002:0da8:0000:0000:0000:0000:1315:7c7a. In addition, instead of using a subnet mask like in IPv4, the new version uses a network prefix length. Leading zeros in the can be omitted so that 2002:0da8::0017:000c can be written as 2002:da8::17:c.
IPv6 addresses can be assigned in different ways: a link-local IPv6 address is automatically configured; router advertisements can be used to assign auto-configured addresses; and a DHCPv6 server can be used to assign IPv6 addresses. For example, a device that supports IPv6 will get an auto-configured link local address that starts with fe80. The suffix is converted into the Extended Unique Identifier -64 (EUI-64) numbering system. The result is something that looks like fe80::1511:aa56:0361:7a4f.
Network devices may also be auto-configured by listening to advertisements sent by routers in the network. These advertisements will define how the network devices should be configured in order to be routable. A routable IPv6 address can be derived by using the information in the router advertisements. This auto-configured address is derived by using the EUI64 address together with the address of the router and network prefix. The router advertisements may instruct the network device to use DHCPv6.
IPv4 networks may use the DHCP server to assign IP configuration while IPv6 may use the DHCPv6 server. In stateless mode, the DHCPv6 server will designate the network servers to use DNS or NTP servers but it will not assign IPv6 addresses for network devices. It has to be done using other methods. In stateful mode, however, DHCPv6 will also assign IPv6 addresses to the network devices, as well as assigning the network servers as in a stateless mode.
Another differentiator between IPv4 and IPv6 is that there is no broadcast in IPv6, only multicast, and unicast of course. (see diagram on the following page) Broadcast and multicast are methods of transmitting data on a computer network. Broadcast means the sender is sending information to all other servers on the network. When a message is sent, all hosts on the network receive the message and process it. Too many messages slow down the network and the hosts connected to it. Broadcasts are not ideal for network video transmissions. Network video products use broadcasts only for specific protocols that require it like DHCP.
On the other hand, multicast is the communication between a single sender and multiple receivers on a network. These technologies are used when many receivers want the same information such as live video simultaneously. This kind of transmission reduces traffic by delivering a single stream of information to many recipients. When compared to unicasting, the biggest difference is that video stream only needs to be sent once whereas with unicast, a copy for each recipient is required. Multicasting is ideal when large numbers of users want to view live surveillance video.
In terms of assigning IPv6 addresses, most programs accept host names and will look up IPv6 addresses. To pass IPv6 literal addresses to a program, there are a few points to consider. When passing an URL, brackets must be used. For example: http://[2001:5c0:84d9:2:240:8cff:fe6b:3cb9]/view/index.shtml. Most programs e.g FTP, Telnet, etc. will accept the IPv6 address in its literal form.
How do you bring IPv6 in gear?
Even if IPv6 is not used by many organizations yet, it is important to plan for the future. It may be prudent now to choose products that are IPv6-ready.
The IP configuration of Axis network products are typically made from the Basic TCP/IP Settings and Advanced TCP/IP Settings pages in the embedded Web interface.
IPv4 is the default setting in most products; however, companies can disable IPv4 or IPv6 configurations. If IPv4 is disabled, the device will only be accessible through IPv6. When IPv6 is enabled, the device will assign a link-local IPv6 address. By default, the device will also listen to router advertisements and assign IPv6 addresses accordingly. Additionally, IPv4 and IPv6 can operate simultaneously allowing users to make the transition in an easy and efficient manner.
Fredrik Nilsson is general manager of Axis Communications, a provider of IP-based network video solutions that include network cameras and video servers for remote monitoring and security surveillance. This is the first of a three-part series Mr. Nilsson is writing on factors that are impacting network video surveillance. The stories will also be featured on www.SecurityInfoWatch.com.
