Essay: Multimedia Networking Challenges And Solutions.

Explain whether the challenge can be addressed in multimedia networking and how it is handled.

Application protocols

(a)  The HTTP is abbreviated as Hypertext transfer protocol. The HTTP is a application protocol in the distributed system, collaborative system and hypermedia systems. The HTTP is a kind of foundation in the data communication on the internet. This is a kind of the structured text. This structured text will use the logical links known as hyperlinks. These links connected in nodes which have data. HTTP can be called as a protocol for the transferring data. When user request for data the HTTP carries a request message to server and get the data.  The first version of HTTP was released in the year 1991 which is called as 0.9. The next version is 1.0 released in the year 1996. The 1.1 version was released in the year 1997. The 2.0 version was released in the year 2015. The HTML is abbreviated as Hypertext markup language. The HTML is a standard of markup language. The HTML is used for creating the pages and applications in web with CCS, cascading style sheets. They also use JAVA script for World Wide Web. This will generally gives the structure of web page [1]. 

(b)  The HTTP 1.1 has many advantages. It has Extensibility which makes compatibility with many other versions and softwares. The Caching will make device faster. It has best Bandwidth optimization. The Network kind of connection management is very good. It has best Message transmission facility. The Internet address related conservation is also good [4]. The Error notification is also better. The Security high is with best integrity and the authentication. 

(c) The cookies are never a good idea. If someone is sending them try to warn them not to do so. You also never try to send them back. If they are sending back again and again try to block them or take serious issue with cyber officials. 

(d) ASCII is abbreviated as American standard code for information interchange. This is a kind of information exchange system for the electronics and communications. The ASCII is generally used in computers and the communication systems. This is one of the best encoding system [3 ]. There are many advantages. ASCII will allow all the computers to use the similar input data and the input characters. This is one of the standard code will allow to create many file possible. The general length of ASCII is 7 bit but the 7 bits will allow to store 128 binary patterns. And so on with the increase in character length and the bit length.

 API is abbreviated as application program interface. The API are set of some procedures

Like protocol and some tools in the process of building software’s and its applications. We know the graphic user interfaces will help the users in many ways, similarly the API will help the programmers for developing new software. This is one way of integration of technology with the business models and other systems. This is one of the best business ecosystems. The APIs are like blocks and one must integrate the blocks. They all must be joined for the forming a good system. The API can be applied to any systems like web technology, data systems, hardware of the computers and many more. There is a concept known as the API calls. In this a call made by the user to server is known as API call or the request.  

Security protocols

In the given problem the Berkeley socket is discussed. Here the socket is a API to the internet with the Unix domain socket are also used in IPC. The IPC is abbreviated as inter process communication.  The IPC is used as linkable modules. The socket is defined as an abstract place or the endpoint in the network or the communication path. The Berkeley socket is a API which tells about the common interface to the input and output for the data. The next type of Berkeley socket is the POSIX sockets. This is also termed as BSD socket. There are few things which are done by the POSIX. They are the conversion of the text address into a packed address. The next one is to convert from the packed address into the text address. The next kind is the forward lookup into a host name or service. The final one is the reverse lookup to host name or the service.  

Let us discuss some of the causes for the above question. In the data communication or the access the team of the network security needs some kind of information for providing the access to the licensing the components.

Some of the best examples for this kind of solution are the explained in the IBM model. In this they need some license key for the server access. This license is known as the floating license key. Few of it are imaged- this is a license manager demon. The next kind is the vendor demon. They are denoted with key names like immortal, the next one is the rational and the final one is the telelogic.

Here the manager demon and the vendor demon both of the demons use the TCP to communicate, the application layer protocol take control of the FLEXnet publisher which is proprietary over the TCP/IP 

When the license manger is involved with sending a hardware key for the client, then there are three cases, first one is the accepted, next rejected and the final one is the expired. If the user is asking the same question after and after for the long time then they must check the process. There is a possible attacks in the communication. There are two cases of attacks, first one is the middle man attack and the next one is the end user attack. These can happen because if the third person is involving in your communication path. The best way to avoid these kind of problems are by establishing the secure communication. Some of them are the encoding the key or data, the next one is the acknowledgement based method.   

(a)  The below system will not use the NAT, this is a non NAT model. This contains the remote clients, which is an end user. The remote client is connected to the internet. The internet access is done with the help of routers. The routers are protected by the firewall [2]. Then they are connected to the web servers of different models like the data base servers, link systems. 

DMZ firewall systems

The DMZ is denoted with the demilitarized zone, the DMZ is also known as the perimeter of the network. The DMZ is a type of the physical or the logical type sub network which contains the external threats facing by the firm. They also show the untrusted networks before the organization is making data transaction between the systems. Most of the issues will help in the presence of the internet. The main purpose of the DMZ is that it will add an extra security for the organization in the local area network (LAN).The external servers or node can access the data only through the DMZ. This is present in the network firewall. The DMZ is present between the node and the private network. In below case, the DMZ is present between the LAN and the external internet WAN [5]. 

The above picture shows the DMZ with a single firewall system. The single firewalls will have at least 3 network interfaces. This will create a new architecture with DMZ. The first interface is with the two internal points. The second one is with the internal server and the firewall. The final interface is between the external node and the DMZ. The main problem with the single DMZ is if the firewall fails the purpose is spoiled [7]. Hence it is necessary to add an extra DMZ. To know the zone it has to represent with as many colors as possible for easy representation. Red, blue and other colors were used differentiating.  

The next one is the DMZ with the two firewall system. 

The above single firewall system disadvantages are corrected with this system. Here 2 firewalls are used for the construction of the DMZ. Among the two firewalls the first firewall is the front end or the perimeter. It allows the traffic from the internal node to the DMZ. The next firewall is named as the back end or the internal firewall.  It allows the traffic from the external node to the DMZ and the vise versa. As there are two firewalls in the system makes the system more secure. If one fails the other will help the providing the security. Generally the firewalls must be chosen in such a way that they are provided by 2 different vendors. This method is called as the defense of the depth.  

The next model is the DMZ with the NAT network address translation.

Here you can see the two DMZ systems with the NAT. This is a more advanced system which not only provides security but also very high-speed data access due to the presence of NAT.

The NAT application is explained through the above model. Here the request from the system 1 and 2 are allowed. But the 3^rd one is not allowed. Similarly, the public access is denied for some systems.

(a) MITM is abbreviated as a man in the middle attack. This is a secret attack which is done in the altering the communication between the two directly communicating systems. Here the control of both users is done by the attacker only. The wifi usage is one of the kinds of example, which is done from the reception end. Here the attacker may target one end or both the ends. Here the second case is the most worst case. The encryption or encoding from both the ends is necessary for avoiding these kinds of problems in the data communication. The encoded or encryption key will help to decode or decrypt at the receiving end [8]. This will end the problem of the middle attacks. The next one is known as the replay attack. The other name for the replay attack is the play back attack. Here the valid data is misused by sending the same data again and again or by delaying a data. This can be done from the receiver end or from middle.

The two possible way of attack is with the tagging and without tagging.

Here the tagging is not present and hence there is every possibility of the attack. Initially, the data request is sent from A to B without tagging. Now due to lack f encoding or encryption, there is a possibility for the middleman attack or play back attack to either side. Hence this is not suitable. Then the B will accept the request and will send the public key certificate. Again there is an addition of new data in the system. In the third step the secret data i.e. item number, price of the product, card details etc [ 6]. Then the B will send final data to the A in a final stage. Here the encryption is not there means it’s a very tragic condition.

In this phase, the tagging is done in the codes. The data encryption and encoding at the source end and the decryption and decryption at the receiver end are done. The codes must be secret and it should not reveal to the third person. When the third person from the internal non trusted person or the cyber attacks may take a chance for the data lost. Or else in all the other situations, the data is safe and the attacks are not possible [14].

The multimedia data generally consists of audio data, video data and sometimes the mix of both. The multimedia data are generally a continuous data. The multimedia data consists of following. They are generally voluminous. The multimedia data are a real-time, which is synchronization with the both audio and the video. The multimedia generally interactive. Some of the best examples of the interactive are the video conference which should be happening at real time without any delay and the other best example is the interactive TV. The multimedia are sometimes burst also, i.e. it is a video on demand. But apart from this multimedia has 3 big challenges. Some of them are There will be a delay in any systems. It is not possible to have accurate or no delay systems. The delay will be varied from system to system and from machine to machine. Here the main aim of the person must be the smallest possible delay. General delay in the apps is ranging from 5 seconds to 10 seconds. The delay may produce the data congestion. One must take care to avoid the data congestion in any form or data congestion due to the delay. The next concept is the packet jitter which tells about the variability of the packets of data in the same stream. The service of the internet is not varied and hence the data delays are not possible to stop. If the same vendor can provide the data variation one can stop the delays for the selected subscribers. The care must be taken for the differentiated services.  

Packet delay and packet jitter are two common methods which will be occurring in the voice over data generally. This also happens in the text and image data also. The care must be taken for avoiding theses steps. The jitter is not suitable for the voice application for the average user. The delay can happen in any point to point of the network. Generally, delay can be measured in two possible ways. The first one is one way and the next one is the round trip delay. The one-way delay calculation is very expensive. It requires very costly equipment and best infrastructure. It is not possible in all the cases. But cost involved in the round trip delay is very less with the equipment of finite or less cost. Generally, the one trip delay and the round trip delay are taken as average for the final delay measurement.

The next kind of thing in the packets analysis is the packet jitter. The packet Jitter is kind of variation in the delay from a certain point to another point. The delay in the data must be varied in a great way if it happens the qualm any of the services will be reduced in a great way. There is a concept known as the depth of the jitter which will give the depth of voice quality. 

The wireless and wired communication uses the data transmission in the form of packets of data. In the packets form the packets will follow certain protocols and the algorithms. In this, the data will be sent in the form of packets in all the direction and in a random path without following sequence. At the receiver end the data received will not be in order and hence the data must be arranged in the proper sequence known as the data resequencing. This process needs the order followed at the transmission end, which helps in the successful recovery of data. This method is done in all the system for the data collection and the data arrangement [13].   

The packet loss is a phenomenon in which the packets of data are lost in the data path which inturn degrades the performance of the system. Packet loss is found in all kinds of data. 

(b) Three types of multimedia networking are:

Some of the common application of the multimedia is internet. On the internet, we can find the 3 basic classifications of the multimedia. The first one is the streaming stored audio and the streaming stored video. The next one is the streaming live audio and the streaming live video. The third and the final classification is the streaming live audio and the streaming live video. Some of the common characteristics of the above are the delay sensitivity, the next one is the end to end to end in the packet delay. The final form of it is the packet jitter. The stream videos are generally having the tolerance to the packet losses. There are a minor disturbance and the occasional packet loss.  In the normal data transmission it will not tolerate the losses. It will not also tolerate the delay variations. 

Streamed live multimedia: Internet radio, internet talk show, Live event, live telecast of sports. Interactive multimedia: IP telephone, The video conferencing, distributed interactive things like video conferencing. 

Let us now discuss the stream stored multimedia. The streamed multimedia is generally having the audio and video files stored on the server. The users will request the audio and video of their own demand for the data and the server will send the data to the user on demand. The next one is the streamed live multimedia. The streamed live multimedia is a kind of live telecast on the internet. It contains the multimedia data like audio, video, text and sometimes the combination of all. This process requires the camera for the recording and coverage, the encoder for the digitize a content. Along with this, a playback buffer is also facilitated. Here the 10 seconds lag in the system can be covered and the delay will be reduced as long as possible. The best example of this kind is the internet radio where many talks are found in this. The options like fast forward of the data, rewind of the data, a pause of the data and the record of the data are found. The final one is the interactive multimedia. In this, they have a certain end to end delay requirements. For the audio requirements, if the delay is in the range of less than 150msec then it is in the category of good, if the delay order is in the range of fewer than 400 msec then it is termed as OK. This has many features like the packetization and the delays are very high in the system. The higher delays will lead to the impair interactivity [12]. There is also a session start known as the initialization. The encoding algorithms also required here. Some of the applications of this type are listed below. They are video conferencing, IP telephone and some distributive interactive.

There are many techniques for the data storage of which the first one is the image compression. Generally, the data compression is applicable for the digital data only. It is not applicable for the analogue data. Generally, the compression performed to reduce the storage cost or the transmission cost. Some of the methods for the lossless compression of the image are run-length encoding. It was one of the default methods for the BMP, TGA and TIFF. The next one is the area in image compression, the area of the image is greatly compressed. There are some predictive coding also used. The next of its kind is the entropy encoding. Some kind of the adaptive dictionaries was also used. The chain codes will also be used in the system. The other kind of technique is the lossy compression. The first one is associated with the colour space. The next one is the transform coding which is using some mathematical operations like Fourier transform, Laplace transform and another kind of transforms for the domain changes. The next one is the chroma sampling which is associated with the colours of the images and the video settings like bright, contrast. The final one is known as the fractal compression.

Let me discuss the problem in two aspects. The first one is the picture version nd the second one is the video version for the zoom. Here the pictures are more quality oriented than the video. The pictures taken with the best cameras are given to the server. But the high-quality images occupy more space compared with the other low quality. Here the images are compressed in the digital format. Now compressed images are zoomed means it cannot give the same original feel. And hence the data must be altered in such a way that the quality must be varied. The next aspect is the video. In the video, the zoom issues will happen at the time of recording. Here the recorded data can be compressed then the quality issues start again. But the Video zooming is not possible. Hence the uploading precaution is the only solution. 

The IP header is a part of the IP packet which has some kind of information at the starting. This header will have many pieces of information like the source address and the destination address. Basically, in present day, they use two different headers. First one is the IPv4 and the next one is the IPv6. The IPv6 has more space.  

The strict route path is a kind of path the packets of data must follow the strict or definite path. The packets must finally go to the destination. This is used for the debugging options. It has many other applications also. 

The record routing is the process in which the route is recorded for the packets of data. Generally in the internet data checksum if the data has a finite route that is the record route then the data will freely flow through the suggested route. If not has to apply algorithms for the data transmission to send the data for the unknown environment. Sometimes the known data might be full then it has to wait for the route clearance and then has to pass the data. Or else the packets of data must choose an alternate path. 

1. i) Identification: The identification is generally of 16 bits. This will use the IP datagram’s. The data value is incremented or decremented depending upon the algorithm followed by the routers.
2. ii) Flag: The flags are generally 3 bits in length. The first bit is kept reserved. The second bit is called as the do not fragment bit. The third bit is known as the more fragment bit.

iii) Offset: The fragment offset is generally 13 bits. This has fragment offset of 8 bytes at the start of IP datagram. This is used in the reassembly of the fragmented data. 

Given the packet offset values is 100, the header length is 20, the value of the total length is 40. The first-byte number is 4 and the last byte number is 31 according to the concept of the above figure.

(d) Why is there a restriction on the generation of an ICMP message in response to a failed ICMP error message? 

Type	Description ICMP Message Types
0	Echo Reply (Ping Reply, used with Type 8, Ping Request)
3	Destination Unreachable
4	Source Quench
5	Redirect
8	Echo Request (Ping Request, used with Type 0, Ping Reply)
9	Router Advertisement (Used with Type 9)
10	Router Solicitation (Used with Type 10)
11	Time Exceeded
12	Parameter Problem
13	Timestamp Request (Used with Type 14)
14	Timestamp Reply (Used with Type 13)
15	Information Request (obsolete) (Used with Type 16)
16	Information Reply (obsolete) (Used with Type 15)
17	Address Mask Request (Used with Type 17)
18	Address Mask Reply (Used with Type 18)

0 means the Network Unreachable, 1 means Host Unreachable, 2 represents Protocol Unreachable, 3 represents Port Unreachable, 4 represents the  Fragmentation is required, but it doesn't fragment the bit set, 5 denotes the Source Route is Failed, 6 gives the Destination Network Unknown, 7 means the Destination Host Unknown, 8 gives the Source Host is Isolated. 9 is Destination the Network Administratively in Prohibited. 10 is Destination the Host Administratively in Prohibited. 11 is the Network Unreachable to ToS, 12 is Host Unreachable to ToS. m13 for Communication in Administratively Prohibited with Filtering. 14 is the Host Precedence for Violation. 15 is Precedence to Cutoff with Effect [11].

(e) The packets of data are reassembled at the output destination but not at the network node. Because it has to flow in packets and also in not a fixed path so it has to alter the flow many times. Hence the data reassemble is best at the destination.

(f) The fragmentation of data is necessary. It is better to fragment before encapsulation because it is easy to re-fragment at the receiver with capsule wise.

(a) CIDR is abbreviated as classless inter-domain routing. This will allocate the IP address for the IP routing. It contains a group of bits and address. Some of them are network prefix, subnet etc. This also includes the variable length of the subnet masking called as VLSM which relates with the prefix arbitrary length.

192.168.2.0/24 for IPv4,

2001:db8::/32 for IPv6.  Format for the IPv4 and IPv6

(b) the Super net block 200.56.168.0/21. 

Similarly 

200=001000000000          

56=01010110

168=000101101000

0=0000

21=00100001 

192.168.98.0 = 000110010010.000101101000.10011000.0000

192.168.99.0 =000110010010.000101101000.10011001.0000

192.168.100.0 =000110010010.000101101000.000100000000.0000

192.168.101.0 =000110010010.000101101000.000100000001.0000

192.168.102.0 =000110010010.000101101000.000100000010.0000

192.168.105.0 =000110010010.000101101000.000100000101.0000 

(d) ISP address block 14.24.74.0/24

The three different organization are

1. i) Organization A This has One sub block with the  120 addresses.

14.24.74.0/24 = 00010100.0010.0100.01110100.0000/00100100

Here the address is modified according to the extension and compression.

1. ii) Organization B

This has One subblock with 60 addresses.

14.24.74.0/24.

The previous data is compressed for the 60 address. Which is half of the first one? Hence it has to be monitored accordingly.

iii) Organization C

This has One subblock with 10 addresses.

14.24.74.0/24

The final one very small and the 10 address is the requested one and we must use the smallest of [place for this. 

The following is the RIP table for the data which is received from the sender.

SENDER CODE	BINARY DATA	RECEIVER CODE	BINARY DATA
Net1 3A	0011 10000	Net2 4	0100
Net2 5C	0101 10010	Net3 2	0010
Net6 3F	0011 10101	Net4 4	0100
Net8 3E	0011 10100	Net6 2	0010
Net9 4F	0100 11000	Net8 2	0010
Net1 3A	0011 10000	Net9 4	0100

(b) The OSFP is abbreviated as open shortest path first. The OSFP is a kind of routing protocol. This is an internet protocol. This also comes under the interior gateway protocol.

(c) i)Area-Border Routers: this has routers in the multiple areas.

1. ii) Internal Routers: All the interfaces are present in the same area.

iii) AS Boundary Routers: These routers are generally present in the boundary of the network. They are sometimes called as backbone area.

(d) BGP is abbreviated as border gateway protocol. This is an exterior gateway protocol.

1. i) Weight: It is the first attribute in the list of data. It is not exchangeable. This is a local element. The path which has the highest weight is preferred.
2. ii) Origin: This is used for the path selection. There are 3 origin codes. They are IGP (i), EGP (e), Incomplete (?)

iii) Local Preference: This is the second in the attribute. This is a local preference.

(e) Dijkstra’s shortest path algorithm  

A to B is 5, A to C has 8 and 10, A to D has 16, 10 and 12.  

t1 = 6, t2 = 16, t3 = 12, t4 = 20, t5 = 4, t6 = 15, t7 =8.

H1= 6+16=22

H2=12+20+4=36

H3=15+8=23 

10.TCP

(a) If the TCP flow control is not properly implemented the silly window syndrome will occur. If the sender is slow and the receiver is also slow then sliding window problem will occur. 

(b)  TCP has two types for the OPEN calls. They are active open and the passive open. The active open is an open call with TCP for establishing a connection. The next one is passive open to which the servers will listen to the calls. 

First the user A asks for the syn, then the server B will acknowledge the syn. The user A also ACK, finally the connection will be established. 

The TCP will use the error control for the reliability. This will detect the following data like the corrupted data, lost data, out of the order data and the duplicated in segment data. The way the error control is achieved with the checksum process. They also use the acknowledgement and the time out also used [10]. 

iii) Mobile Host: This is the combination of the software and the data which flows from one system to the other. This is generally code which travels inside the network nodes. 

1. i) Care of Address: This is associated with the nodes in  two different ways mentioned below. Foreign agent care-of address(FACoA): This is for all the foreign nodes who has the similar address like home network. Co-Located Care of Address: This will happen if the foreign nodes are not deployed. 

Initially the servers will active the end users. Then the home agent connects all the servers and clients to the foreign agents with the address and the care of address mode. They might be mobile users or PC. The corresponding nodes will used for the data transmission. 

The main advantages are it is not necessary to follow the protocols of the foreign system and the next advantages are it will access data quickly than the other time when it is its home network. The disadvantages are the data speeds may be slow due to the difference in the protocols. And the next kind is that it may have to wait for long time to send the data to its home network [9].  

References

[1] J. Hill, R. Szewczyk, A. Woo, S. Hollar, D. Culler and K. “Pister. System architecture directions for networked sensors.” In Proceedings of ACM ASPLOS IX, November 2000.

[2] Perrig, A., Szewczyk, R., Wen, V., Culler, D., & Tygar, J. D. Spins: Security protocols for sensor networks. Mobile Computing and Networking 2001.

[3] Wang, Y., Ramamurthy, B., & Xue, Y.  A key management protocol for wireless sensor networks with multiple base stations. CSE Conference and Workshop Papers, 2008.

[4] Wang, Y., Ramamurthy, B., & Xue, Y. Digitalcommons@university of nebraska – Lincoln, 2008 . Retrieved from https://digitalcommons.unl.edu/cseconfwork/111 

[5] Xue, Y., Lee, H. S., Yang, M., & Kumarawadu,, P. Performance evaluation of ns-2 simulator for wireless sensor networks. 0840-7789/07 ©2007 IEEE,

[6] Söderlund, R. Energy efficient authentication in wireless sensor networks. LITHIDA/DS-EX--06/012--SE, [19] Perillo, M. A., & Heinzelman, 2006.

[7] Adrian Perrig, Ran Canetti, J.D. Tygar, and Dawn Song. “Efficient authentication and signing of multicast streams over lossy channels.” In IEEE Symposium on Security and Privacy, May 2000.

[8] Karlof, C., Sastry, N., Wagner, D. TinySec: A Link Layer Security Architecture for Wireless Sensor Networks. ACM SenSys 2004, November 3-5, 2004.

[9] Y.C. Hu, A. Perrig, and D. B. Johnson, “Wormhole detection in wireless ad hoc networks,” Department of Computer Science, Rice University, Tech. Rep. TR01-384, June 2002.

[10] P. Apostolos, "Cryptography and Security in Wireless Sensor Networks," FRONTS 2nd Winterschool Braunschweig, Germany, 2009.

[11] Zhu, S., Setia, S., Jajodia S., LEAP: Efficient Security Mechanisms for Large-Scale Distributed Sensor Networks. In The Proceedings of the 10th ACM conference on Computer and communications security, 2003.

[12] Modares, H., Salleh, R., and Moravejosharieh, A. Overview of security issues in wireless sensor networks. Third International Conference on Computational Intelligence, Modelling & Simulation, IEEE, 2011.

[13] M. A. Abuhelaleh and K. M. Elleithy. Security in wireless sensor networks: Key management module in sooawsn. International Journal of Network Security & Its Applications (IJNSA), 2(No. 4), 2010.

[14] Mohanty, P., Panigrahi, S., Sarma, N., & Satapathy, S. S.  Security issues in wireless sensor network data gathering protocols: A survey. Journal of Theoretical and Applied Information Technology, 2010.