Streamyx

So, you got yourself a new iPod and now are pondering over the tempting option of iPod music downloads available on the web. Indeed, these sites seem like a treasure found at a few mouse clicks. But before you jump at the first website that offers iPod music downloads, do your homework and get to know your choices better.

Largely, all sites providing iPod music downloads are either free or paid. Naturally, the first ones sound more appealing, but only until you look at them more closely. In general, anything that comes free on the Internet should alert you and make you think twice before you decide to yield to all the too-good-to-be-true promises. The same goes to free music for your digital player.

Music available on the web for free downloading has raised numerous issues regarding copyrights. And while a lot of these sites get banned or face law suits, new ones pop up almost every day. Of course, it is up to you to what extent you are ready to go, being aware that you are violating the law, but in most cases the risk you take is not worth it.

Free iPod music downloads often come in pathetic quality, many songs are incomplete and the downloading process takes ages. Should you have any problems with the site, there is no customer support to help you. But this is still not the worst thing about free music sites - any file you download from them may expose your computer to adware, spyware and viruses. There is simply no responsibility and no means to check each music file that is uploaded on the website, because the majority or all of them are shared by other users.

The only advantage of the sites offering free iPod music downloads is that they are used as a platform for aspiring singers and musicians to introduce their talent to the world. In this case you have no problems with copyright, because this music is shared by the authors themselves.

Don't feel disappointed though. Quality iPod music downloads are very much available, and the cost is not a problem for the majority of folks, even students and teenagers. Though the most popular website must be iTune, it charges per download, and the overall amount can add up quickly. As an alternative, there are websites, which give you an access to unlimited music and songs for a one-time membership fee or a yearly subscription.

Rest assured, these sites are legal, secure for your PC and normally provide you with free software for file format conversion (just check to ensure it is compatible with your computer). The selection of songs is virtually unlimited and all the latest hits as well as less known pieces are easily researchable. For any music lover with a bit of common sense it becomes obvious that unlimited iPod music downloads at a price of 2-3 regular CDs is an awesome deal, worth every cent of it.

Why not start transferring the latest album from my blog to your player now?

Davion is crazy about iPods. Discover how you can access unlimited iPod music downloads instantly for less than a dime each. Also, read another of his popular article on iPod music downloads.

DNS block lists can be a nice way to reduce the amount of email spam
received by a mail server. They are usually cheap, easy to install and
resource-friendly. As the name implies they work with the help of domain
name servers. If a mail server uses DNS block lists it queries a name server
for the address of a name built from the hostname or IP address of the sending
mail server and the name of the block list. Depending on the result of the
query the mail message gets accepted or rejected.

Probably the first DNS block list was the Realtime Blackhole List (RBL)
started by MAPS (Mail Abuse Prevention System). It is now a service you have
to pay for but the majority of DNS block lists is still available for free.

It is easy to include DNS block lists in the configuration of the most common
mail servers (sendmail, postfix, exim, ...). The block lists are integrated on
the server side and you save bandwidth because you don't need to receive the
spam mails. The connections are rejected in the SMTP dialog between the
sending and the receiving mail server. DNS block lists use a very low amount
of resources from your mail server compared to spam or virus filters that have
to analyse the contents of your mail messages.

Of course there are disadvantages also. Probably the most important
disadvantage is that you are outsourcing the decision whether you accept or
reject mails from a certain source. If the sending mail server is listed in
one of the blocklists you are using you will reject every mail from this server.
Usually you will not know the administrator of the blocklist but you have to
trust him that he adheres to the policy of the blocklist. Even if the admin is
trustworthy sometimes there will be mail servers listed that should not be on the
blocklist. Imagine an ISP who has a lot of good customers but one customer who
is a spammer. If the spammer sends out spam over the mail server of the ISP,
the mail server may get listed on a blocklist. It will need some time until the
ISP solves the problem with his bad customer and gets his mail server off the
blocklist. In the meantime you will not receive mail from the good customers
of this ISP. Another problem is that DNS blocklists don't live forever. If a
blocklist is abandoned and your mail server still tries to query it, you may
block mails that you wanted to receive.

So how useful are DNS block lists after evaluating the pros and cons?
They can be very useful to lower the overall CPU usage of your anti spam
strategy. It is advisable to use a small number of carefully chosen
blocklists. If you are using a block list, subscribe to the mailing list or
newsletter of the organisation who runs the block list. That way you will take
note of any problems that the block list may have and you will be informed if
it gets shut down. DNS blocklists should never be your only strategy against
spam. They should be combined with other mechanisms to help keeping spam out
of your inbox.

Andreas Stiasny runs a small ISP business and has been configuring mail and web servers for more than a decade. For more information about DNS block lists and other anti spam strategies visit http://reduce-spam.com/dns-block-lists.php where you can find information about server side as well as client side tools which help to reduce the amount of spam mails.

Most Asian cellular carriers mulling over 3G have chalked out at least tentative transition paths towards that Holy Grail. If theyre GSM networks, its a safe bet EDGE (Enhanced Data for GSM Evolution) is being considered, to replace/augment GPRS for high speed data services. Because EDGE uses a new modulated scheme that is also used for UMTS/3G, EDGE becomes a sort of half-way house to 3G.

The cost to introduce 3G into an existing GSM network is enormous. A large portion of 3Gs non-license related costs pertain to new nodes patched into an existing GSM network to make it 3G compliant. And of course, these new nodes need to inter-operate with existing 2G and 2.5G nodes.

An alternative does exist, that until recently dare not speak its name. Marrying cellular and WiMax/WiFi clouds, is not just cheaper, but more in keeping with the times. Besides the cost benefits, such a union addresses two other big issues: bringing high speed data services with laser like precision to the urban users who need them and voice connectivity over cell phones to suburban residential homes with poor cellular reception.

Integrating selected WiFi Hot spots or WiMax Hot Zones into a cellular network requires an IP Network Controller (INC), an IP access network, a patch to allow the Wireless LAN (WLAN) access network to issue the relevant accounting information to the cellular clouds AAA (authentication, authorization, and accounting) server and an investment in IP roaming. Barring a few more widgets, thats essentially it.

Given the simplicity of such a solution, anyone who has seen engineers sweat over cell site deployment or attempted to work the math behind the cellular hex grid, has to wonder why the cell phone-wallahs have not already adopted WiFi/WiMax at their peripheries.

One however continues to sense discomfort in cellular circles over any open discussion on WiFi/WiMax. This may have something to do with the fact that the same user who demands everything be free on the Internet, is more than willing to pay a premium for his mobile service. The cellular carrier therefore, is understandably wary of encouraging bad habits in his paying customers.

Kineto, an equipment manufacturer, explains how such an eco-system would work.

- A subscriber with a WLAN, dual mode mobile phone moves within range of an access point to which the handset can connect.

- On attaching, the handset contacts the mobile operators INC over the IP access network, to be authenticated and authorized for mobile service access.

- If approved, the INC updates the subscribers location information in the network. From that point on, all mobile traffic is routed via the INC and over the IP access network. The subscriber is now on Voice over Broadband (VoB) and on a lower fixed line / VoB type tariff.

- When the subscriber moves outside the range of the serving access point, the INC facilitates roaming to the licensed outdoor network. The roaming process is completely transparent to the mobile subscriber.

- In addition, if a subscriber is on an active voice call or handset data session when they come within range (or out of range) of a service access point, the INC facilitates the handover of the active call between networks. The handover is completely transparent to the mobile subscriber.

- The WLAN access network issues the relevant accounting information to the cellular networks AAA server. This accounting information can then be incorporated into the operators specific CDRs enabling it to be assimilated into the operators existing legacy billing system, creating a single bill for Cellular and WLAN usage.

In divvying up responsibilities, the WLAN provider manages the network while the mobile operator looks after customer care and billing. The end-user pays his mobile operator for the usage of the WLAN. The charges for using a cell phone over a WLAN would be lower than cellular use but in most cases it would be incremental revenue that the cellular companies would otherwise lose to fixed-line or VoB networks.

The cellular-WiFi/WiMax eco system also ropes in homes and offices equipped with broadband. To connect, the home or office user goes to his mobile providers web portal and registers his WLAN into the IP Network Controller (INC). The subscribers cell phone is now patched into the WLAN and on a lower fixed line / Voice over Boradband (VoB) type tariff.

While there is growing competition in the VoB sector, only the cell phone operator decides whether the customer can get a combined cellular+VoB bill. A mobile providers Cellular-WLAN service shall therefore, stand head over shoulders over any Vonage type VoB service.

As we have seen, in a Cellular-WLAN eco system devices intelligently pick and choose from the wireless network offering the strongest signal or lowest price in a given area. It is a compelling picture that demands the cellular operators attention, more so in Asia.

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References & recommended reading

Books:
GPRS Demystified by Hoffman, John
GSM, GPRS and EDGE Performance : Evolution Towards 3G/UMTS
by Timo Halonen (Editor), Javier Romero (Editor), Juan Melero (Editor)
WLANs and WPANs towards 4G Wireless by Ramjee Prasad, Luis Munoz

White papers
Public Wireless LANs for Mobile Operators by Philippe Laine of Alcatel.
GSM to 3G, Evolution or revolution? by Hughes Software Systems & Adax
Europe Limited.
Handover between WCDMA and GSM by Gertie Alsenmyr,Joakim Bergstrom & others of Ericsson

Websites
http://www.gsmworld.com
http://www.cdg.org
http://www.kinetowireless.com
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BRAHAM SINGH joined PCCW in January 2001 and founded their international IP backbone & service company now called BtNAccess after its merger with Corporate Access, one of Asias largest satellite based service provider. Today, BtNAccess is an established global carrier, offering enterprise & carrier grade services over its MPLS enabled network. Services offered include