Network Services - SkyNet-SH

Hello and welcome to another post, here at SkyNet-SH.
Today I will be introducing you to network services, explaining what services are available and how they have developed over their timelines.

Network Services

Packet Switches:

Packet switches is a mechanism which sends network traffic in small manageable data units across the system. When you would like to send a file across to somebody else, the file breaks down into smaller sizes like 2MB for example and sends it across the internet in manageable chunks.

The benefits of packet switches are that it only functions when there is a group of routers or WAN switches are all interconnected, this is reliable because if one line of the branch fails then the data you would like to send (packet switches) will redirect to a different route line. You would use packet switches to direct traffic via a variety of routes such as through a mesh topology which is efficient in speed.

Big companies with lots of employees would use this as it is much better than having cables due to the amount of cost and space it requires, therefore if they have many customers it means it is easy for it to be expanded.

Figure 1. Packet Switch Diagram (Webclasses.net, 2015)

However, the limitations for this is the time it requires for the data packages to be put back together as it is broken up in the first place and is not ideal for emergencies. Furthermore, it usually splits into packets of 600 bytes (60k approx.) so if a file is 512 bytes, it will require two packets doubling the time needed.

Another limitation is if the main cloud fails down the whole mesh topology will follow.

ISDN:

ISDN stands for integrated services digital network. It is an old circuit switched system for simultaneous digital transmission of voice, video, data and other network services (it is still in use for some places but technology has advanced and grown out of it slightly). ISDN was the first solution to transfer data and bypass the limitations set by the public telephone system in 1980’s.

The benefits of ISDN are that it can hold multiple connections by having separate channels for data. This gives it the capability to send voice and data simultaneously. It can also be used for ‘other signals’ by other organisations for different purposes.

Another benefit of ISDN network line is that it could be provided in two different ways. The first way is BRI (basic rate interface) and the second way is PRI (primary rate interface). BRI is for smaller businesses and smaller remote sites whereas PRI is for larger businesses, communities and organisations. This is because BRI can have two channels of approximately 60kb, each for voice and data communication signals. On the other hand, PRI can have 30B channels of 64K, allowing up to “30 voice lines” which are suitable for business purposes, (Anderson et al, 2011).

In addition to this, nowadays the modern ISDN connections are considered faster than traditional dial up connections because more development and research has been invested.

Figure 2. ISDN Diagram (Mynetfone.com.au, 2015)

The limitations are that ISDN can be very costly because it requires specialised digital devices.  This network service would be used for connections in remote sites, or for customers such as a small business or home users. Additionally, a limitation is that the resources you send outside to the other networks will not be permanently available to other internet users; this is because ISDN functions in a way where you send video, voice, and data that cannot be retrievable afterwards.

Lastly, the last limitation of ISDN would be that modern ADLS (asymmetric digital subscriber line ) connections can transfer a lot more data in one go and are cheaper to maintain, putting ISDN below it as it has “no balance or symmetry”, (Anderson et al,  2011).

ADSL Broadband:
ADSL Broadband, (Asymmetric Digital Subscriber Line) has high speed for data transmission in which a single line or cable is capable of carrying large amounts of data at once. The most common form of broadband connections is cabled modems which provide a continuous connection to homes and businesses.

The benefits of broadband are that it is considerably faster than its predecessor baseband with technological advancements. Furthermore, another benefit is that it is easy to set up nowadays as technology has advanced to the stage where the entire physical network infrastructure is all built into one ‘hub’ – making it easier to handle by people with no prior knowledge of the communication devices. The third benefit is different service providers now offer different packages making it easy to find the right one for you for the right purpose such as if it was purchased for a business or if it was purchased for residential purposes.

Figure 3. ADSL Broadband Configuration Diagram (aitelephone.com, 2015

One limitation of broadband would be that if you have two systems connected to the broadband but one if very far away and one is very near, the connection strength is prioritised towards the nearer system. This is because it doesn’t include a switch to regulate signal strength to all systems. Another limitation would be that the advertised download and upload speeds are rarely what they’re advertised to be. This means that you could be paying £100 a month for a 100MB/s speed when realistically you’re only getting 10MB/s (the density of area and other interference can be a role).Lastly, ADSL Broadband is not well suited for all internet applications. This is because the ADSL "pipeline" to send data is quite small. Internet applications such as websites and VPN (Virtual Private Networking) are not well suited for ADSL Broadband as the way data is transmitted is different than usual. It may also be improved only if it has fibre optic cables rather than copper wires as then it travels faster.

Wireless Access Protocol
Wireless Access Protocol which is often abbreviated to as WAP, is a wireless specification that was originally restricted to mobile phones, however this has now been opened up in order to cater for smartphones and other handheld devices. WAP allows the transfer of data to be transmitted to other wireless devices without the need of the same wireless technology. This means that both devices do not need the same wireless technologies as each other in order to be able to connect and communicate. 

The server in which WAP is based from, is a computer that can receive, process and then respond to the connected user's request, often responding with the requested information, unless there is an error with the data or network. This is often a problem with wireless devices that transfer data.

Figure 3. WAP Server Diagram (Wirelessdictionary.com, 2009)

Figure 3 shows the process in which data from the internet is received and then processed on the HTTP and WAP servers.

Data that is from the internet must be accessed via HTTP servers before being fed through the WAP server. When the WAP server receives the data, it is processed before being sent on to the device that initially requested the information. Once the WAP server has responded to the user with the specified information, the user is free and able to view the webpage or internet-based data.

The benefits of Wireless Access Protocol are that due to its compatible hardware with many other devices and wide-usage, the technology is being upgraded and updated all the time, for example recently 3G, which is a well known and commonly used form of communication software, has been upgraded to 4G which is basically identical, except for being noticeably faster in terms of download and upload speeds.  Another benefit of WAP is how effective the technology is for mobile devices, as it allows them to access and send information wirelessly, such as texts and data transfer.

However, there are limitations regarding Wireless Access Protocols and these are the speed at which data is transferred. Regarding text messages, sometimes it can take a few hours or even days to reach its recipient which can prove to be fatal, in the case of an emergency or urgent event. Another limitation is the content that can be sent over the protocol. Sending media such as videos and images often require a high amount of storage memory, which is rarely seen on mobile-devices and even if it were available, the media would not be able to send due to high files sizes and WAP's low bandwidth. This means the speed at which the content would upload, process and send would take a considerably long amount of time and memory.

SkyNet-SH

Thank you for reading through today's post all about 'network services' and what they can offer.

References:

Wireless Access Protocol (WAP) - Wirelessdictionary.com, 2009. Wireless Access Protocol - WAP [online] Available at: <http://www.wirelessdictionary.com/wireless_dictionary_WAP_definition.html> [Accessed 02/2015]