Checklist before you buy an 802.11n wireless

1 - MIMO

One of the big advantages of 802.11n is MIMO.MIMO is short for Multiple Input / Multiple Output. MIMO breaks the data transmission down to multiple parts that are sent separately to the client, where they are reassembled. One of the requirements for this then is multiple antennas to send and receive the data. This system has the advantage of extending the range of wireless, along with increasing the capacity that can be carried by the signal. MIMO is implemented in almost all Draft N and Pre N specs. The use of MIMO in these devices has, for the most part, greatly extended the range of these devices. Unfortunately, there are still debates ongoing about the finalization of MIMO itself, as the 802.11n spec is not ratified yet.

2 - Standard not fully ratified

IEEE has not fully ratified the standards for 802.11n. This means that the technical details of 802.11n have not been decided upon. The original draft for 802.11n was voted on earlier this year and soundly rejected, receiving only 46 percent of the needed 75 percent of votes to be accepted. Draft 2.0 of the spec is scheduled be debated and approved in March of 2007. Items adhering to this spec can be labeled as Phase 1 Draft N. These items will be compatible with each other (unlike many current pre-n and draft n components). The final ratified standard will probably be ratified in early 2008. Of course, if no Draft 2.0 can be agreed upon in March 2007, this will push the schedule for all of this back.

3 - Equipment cannot guarantee N compatibility

As the final spec of 802.11n is not fully ratified, it is impossible to guarantee that any equipment sold as Pre-N or Draft-N will be compatible with the final spec. Many manufactures on banking on the assumption that compatibility can be achieved by firmware updates to their equipment. Currently the only vendor offering a full replacement warranty should there equipment not be compatible with the final spec is Asus.

4 - Huge speed increases over 802.11g

The final 802.11n will undoubtedly boast a great speed increase over 802.11g. This boost will almost assuredly make wireless faster than 100mb Ethernet. Currently most Pre-N and Draft-N equipment are already showing great speed increases. The speed they operate though varies based on manufacturer and equipment. The advertised speeds vary from 100mb to 200mb. If you truly need greater speed, be very careful in your shopping to make sure you are getting the fastest speed possible.

5 - Backward compatibility with previous wireless standards

While IEEE has announced that any final spec for 802.11n will include backward compatibility for 802.11b and 802.11g this specification is not finalized. With this being the case, there can be no guarantee of backward compatibility for current Pre-N and Draft-N gear. While most of the products currently on the market offer backward compatibility, how they implement it varies from vendor to vendor. Due to this, there can be (and have been reported) many instances where gear labeled as backward compatible, have not been fully backwardly compatible with equipment from other vendors.

6 - Draft-N and Pre-N gear may not be compatible with Draft-N and Pre-N gear from other vendors

Currently in the Draft 1.0 of the 802.11n spec, there is nothing to guarantee compatibility among equipment. If you choose to use Pre-N or Draft-N gear you will need to buy all of your equipment from a single vendor. While interoperability may be promised, there is no way to guarantee this. The Draft 2.0 spec of 802.11n will include interoperability standards for the release of Phase 1 Draft-N gear.

7 - Testing has shown MIMO systems not based on Draft-N standards can be significantly faster than systems based on Draft-N

Real world testing has shown that highest possible speeds using MIMO can be achieved by not sticking to the Draft-N specifications. What this means is that if you are truly searching for the fastest possible wireless connection, do not force your search to just N class products, but products that use MIMO.

8 - Draft-N gear is driven by marketing

It has been several years since any new development was made in consumer grade Wi-Fi. This has lead to a certain degree of stagnation within the market. The advent of Pre-N gear has given companies something to latch onto in an attempt to offer their customers something new. While there are undoubtedly benefits (in speed and range) to using this new gear, you are also putting yourself in line for potential problems. You really need to weigh your actual needs before jumping on the bandwagon of a "not ready for prime-time" technology.

9 - Potential to interfere with existing Wi-Fi

One of the issues with MIMO is that it uses a wide spectrum (40MHz) to send its data. Currently only three (1, 6, and 11) of the available channels in the current 2.4 GHz band are considered to be non-overlapping at this spectrum. However, under a powerful signal they can overlap. What this means to you is that if you have multiple wireless networks running, your Pre-N gear will need to be on one of these 3 channels, possibly necessitating a change in your current wireless networks. Also, you will want to plan for the overlap if possible, by moving your current networks to channels not sequential to 1, 6, and 11.

10 - Issues with media streaming devices

One issue that has been reported with Draft-N and Pre-N gear is that it appears it have some issues with various media streaming devices. This is an extremely perplexing issue, as of the goals of 802.11n was the ability to stream high definition media wirelessly. Whether this is due to issues in the Draft 1.0 specs, or if it's an issue with the current generation of media streaming devices remains to be seen, but at the moment a wired connection remains your best bet for streaming.

IPv6 the Protocol

As everyone of you knows, TCP/IP is the communication protocol of the Internet. To be precise, TCP/IP is a suite of protocols. The TCP (Transmission Control Protocol) provides a reliable bidirectional connection between two hosts, using the communication facilities provided by the IP (Internet Protocol). In fact, IP is a network layer protocol and its task is to deliver packets of data from a source host to a destination host.

IPv6 is the new version of the Internet Protocol, that is meant to replace IPv4 (which is the version currently in use) in a few years. IPv4 has been used since the Internet was born and has worked very well until now, but it has many serious limits that IPv6 has been designed to overcome. As you may guess, there have been many changes from the definition of the IPv4 protocol to the one of the IPv6 protocol.

First of all, IPv6 provides a larger address space than IPv4. As many of you know, IPv4 supports about 2.000.000.000 addresses. You may think that such a large number of addresses should be more than enough for the actual size of the Internet. This is partly true. In fact, until recent times, IPv4 addresses have only been allocated in blocks of 254, 65534 or 16777214. This has lead to an enormous waste of usable addresses, since many organizations have been forced to ask many more addresses than the ones they really needed. The waste of IPv4 addresses has been of such an order of magnitude that the whole address space will be soon completely exhausted. Now the IETF has developed a wiser address allocation policy: CIDR (Classless Inter-Domain Routing). However, while CIDR has been designed to achieve the minimum waste of the remained IPv4 addresses and to minimize the growth of the routing tables (due to the non-hierarchical organization of the IPv4 address space), it does not solve the problem of the upcoming exhaustion of the IPv4 address space. Here comes IPv6: it provides more than a billion of billions addresses per square meter on the Earth! Besides, IPv6 uses a CIDR-style architecture for address allocation that prevents a big waste of addresses and an uncontrolled growth of the routing tables. So, while CIDR partly addresses the problem, IPv6 represents the long-term solution.

Furthermore, IPv6 has been designed to satisfy the growing need of security experienced by the Internet community. The authentication header mechanism allows the receiver to be reasonably sure about the origin of the data, and the IPSEC privacy facilities provide end-to-end encryption of data at the network layer. IP spoofing attacks and eavesdropping of data will be much more difficult in the Internet of the next millennium. However, as Wietse Venema points out, network-level encryption poses new security problems. In fact decryption puts a considerable overhead on the CPU and this may eventually leave the host more vulnerable to flooding-type DoS attacks. To reduce these risk, a careful implementation of the networking protocols is required.

Moreover, IPv6 has many improvements for mobile networking and real-time communication. In particular, unlike IPv4, IPv6 has robust autoconfiguration capabilities that simplify the system administration of mobile hosts and LANs.

Although IPv6 is superior to IPv4 in everything, it is a common opinion that the transition from IPv4 to IPv6 will be long (perhaps more than a decade) and difficult. In fact, many organizations have made an enourmous investment in IPv4 technology and are not ready nor willing to speed up the transition yet. IPv4 is a well-known, and thoroughly-tested technology; its reliability and its widespread use represent a major slowing-factor in the development of IPv6.

Today, there are only a few working IPv6 implementations. Hope that the porting process of old IPv4 software to IPv6 and the development of a fully IPv6-enabled Linux distribution would catch pace.

Get free software every day

Get free software every day at Connect.On the side bar you can find free licensed software under the heading of Giveaway of the Day.Giveaway of the Day gives you one free commercial software application every day. What's the catch? Each program is available for 24 hours only, and you must install it the day you download it.

To clarify, the software doesn't expire after 24 hours. Rather, you have a 24-hour window in which to nab it and load it. But once that's done, it's yours to keep. Sweet! So visit the Connect everyday to get Giveaway of the day. Connect and get it