Data Communications 2 Module 3

Module 1 Global Network Management

In this module there are three topics. We study the key technical issues for managing global networks based on Internet technology.

1. Open standards
2. Network management
3. Network security

Module 3, Topic 7 Open standards

Aims

At the end of this topic you should have:

• a knowledge of the types of standards in use in global communications;
• a knowledge of the standards bodies setting Internet related standards;
• an ability to locate standards and strategy papers relevant to the Internet using Internet technology;
• developed an attitude of critical inquiry in relation to the concept of industry standards.

Syllabus

• Open standards
• Types of standard,
• Internet standards bodies,
• Some Internet related standards

1. Types of standard

Formal standards are written documents developed according to a set of well known procedures by a standards setting organisation. Industry standards are set by common usage. If enough copies of a product are sold and used, new purchasers might buy clone products built to copy (in function) the industry standard product.

Open and proprietary are descriptions of industry standards. If an organisation uses the law to enforce its copyright and other forms of intellectual property rights (for example trade secrets and patents), then the industry standard is said to be proprietary. If an organisation makes its product specification public property, then the standard is said to be open.

The term open has taken on other meanings over time. Unix is said to be open, certain SQL database packages are said to be open, etc. The term here is applicable because these products satisfy the definition of open above.

Hence, standards are either:

1. Formal or
2. Industry. In tern Industry standards are either:
1. Open or
2. Proprietary

2. Internet standards bodies

Visit each of the home pages below, try to identify what the organisation does as a primary mission, who sits on the standards committees for this body, what areas of standards does this body cover.

2.1 IETF

The Internet Engineering Task Force (IETF) is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It is open to any interested individual.

The actual technical work of the IETF is done in its working groups, which are organised by topic into several areas (e.g., routing, transport, security, etc.).

Many see the IETF as the Internet standards body.

2.2 ISO

The International Organisation for Standardisation (ISO) is a worldwide federation of national standards bodies from some 100 countries, one from each country.

ISO is a non-governmental organisation established in 1947. The mission of ISO is to promote the development of standardization and related activities in the world with a view to facilitating the international exchange of goods and services, and to developing cooperation in the spheres of intellectual, scientific, technological and economic activity.

ISO's work results in international agreements which are published as International Standards.

2.3 ITU

The International Telecommunications Union (ITU) is an international organisation within which governments and the private sector coordinate global telecom networks and services. ITU activities include the coordination, development, regulation and standardisation of telecommunications and organisation of regional and world telecom events.

2.4 W3C

The World Wide Web Consortium (W3C) was founded in 1994 to develop common standards for the evolution of the World Wide Web. It is an international industry consortium.

2.5 IEEE

The Institute of Electrical and Electronics Engineers (IEEE) claims to be the world's largest technical professional society. It was founded in 1884 by a handful of practitioners of the new electrical engineering discipline in the U.S.A, today's Institute is comprised of more than 320,000 members who conduct and participate in its activities in 147 countries.

The technical objectives of the IEEE focus on advancing the theory and practice of electrical, electronics and computer engineering and computer science. To realise these objectives, the IEEE sponsors technical conferences, symposia and local meetings worldwide: publishes nearly 25% of the world's technical papers in electrical, electronics and computer engineering; provides educational programs. The IEEE runs an active and influential standards setting system.

3. Some groups of Internet related standards

For each of these groups of Internet standards, locate a copy of the suggested standard and read it just until you understand what that standard is about.

3.1 RFCs

Look through the following pages. What is and RFC? Why does it have that name?

What is RFC822?

• Internet standards index
• Requests for Comments index (long 250 Kbytes)
• RFCs are available in full text form with and index on CD Rom from Walnut Creek CDROM, a source of public domain software on CD Rom.
• RFCs are available on line in here Australia.

3.2 HTML

What is the latest version of HTML? When were the various versions first released? What will be the next version of HTML? What special features will it have over the previous version?

The HTML standards are set by the W3C. Browser writers create software capable of displaying standard HTML with extenuations, for example here are the features of two browsers Microsoft Internet Explorer Version 3 and Netscape Navigator version 3 each standards compliant with enhancements. The standards body tries to keep up with the developments. The Data Communication 2 Reader has a review of browsers comparing features and extensions to the standards, see reader article number 10, Ayre, Rick and Mace, Thomas (1996) Online Internet access : just browsing, in PC Magazine, Volume 15, Number 5, March 12, 1996, pp. 100-146.

A writer of HTML can check to see their HTML is standard, Microsoft or Netscape compliant by using an HTML validation service such as that linked here.

3.4 DCOM

Where is DCOM formally specified? What is the relationship between DCOM and Network OLE? What is OLE?

Microsoft is making it's Distributed Component Object Model (DCOM) available in the public domain, it may become a standard. I present it here as a candidate industry standard still, a proprietary specification on its way to an standard. Not everyone thinks it will get there. Here is a contrary view. Our text book also contains information on DCOM.

Required reading

The web sites referred to above must be visited, also read:-

Ayre, Rick and Mace, Thomas (1996) Online Internet access : just browsing, in PC Magazine, Volume 15, Number 5, March 12, 1996, pp. 100-146.

Orfali, Robert, Harkey, Dan and Edwards, Jeri (1996) The essential client/server survival guide (2nd. ed.), John Wiley & Sons Inc. pp. 675. Read about the web standards in chapters 28, 29 and 30.

Exercises

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Module 3, Topic 8 Network management

Aims

At the end of this topic you should have:

• a deeper knowledge of some technical features of the Internet, especially the Simple Network Management Protocol (SNMP);
• a knowledge of some new developments in network management and desktop computer management;
• demonstrated skills using basic network monitoring tools like ping, traceroute and nslookup;
• assimilated attitudes appropriate to the management and monitoring of Internet infrastructure, especially the attitude of openness;
• demonstrated the ability to install and operate simple network manegment software.

Syllabus

In this module you will search for, and find material on the emerging desktop management standards, use basic network monitoring software (available in Windows 95, Unix and Microsoft TCP/IP for Windows for Workgroups 3.11). You will down load, install and operate a public domain package for network management and use web based network monitoring tools.

Network management

• Desktop Management
• SNMP
• ping
• traceroute (tracert)
• nslookup
• network throughput monitoring
• SNMP monitoring software installation

1. Desktop management

The Desktop Management Task Force (DMTF) has specified a standard, the Desktop Management Interface (DMI). This is the new and upcoming standard for future Internet component management. Read about the features in the DMTF home page, and the DMI standard in your text book (Orfali et. al. p. 609 - 624).

Here is a quote from the DMTF white paper on DMI:-

2. SNMP and prior systems for management

This is the current standard for network management. It involves ICMP protocol packets. Use the commands below on your system (most TCP/IP systems have these commands or programs that do the same thing) to see what can be done to monitor network components and their operation with SNMP.

The text, Orfali et. al. 579 - 605 has a good description of SNMP, read it.

ICMP is an Internet protocol that helps manage IP networks. The following are some simple commands based on ICMP.

ping

The ping command send an IP packet to a host, if the packet arrives, the host returns an IP packet which on returning to the sender, allows the sender to determine the transit time. These are called ICMP packets. There are many other types of ICMP packets.

Try ping to your own PC (the route command will allow you to find your PCs IP address)

Try ping to your gateway, try ping to broncho.ct.monash.edu.au.

traceroute (tracert)

The Unix command traceroute (Microsoft tracert) allows you to send tree ICMP packets to each gateway computer between your PC and another host. This command alows you to see where and why you can't contact a host, and see the "structure" of the Internet.

Try traceroute (or tracert) to broncho.ct.monash.edu.au and to a USA site like say www.hp.com.

nslookup

If you have a Unix account, locate and use the nslookup command, this allows you to learn about the machine names and IP address numbers.

network throughput monitoring

The following web address demonstrates the use of the www to monitor data throughput in parts of the web. The software used is public domain and can be installed and operated with your Unix web server, see the Multi Router Traffic Grapher page for details.

View the Monash traffic data, see how it changes over time.

3. Some SNMP software

You may wish to install a demonstration network monitoring and mapping package for IBM PC clones running TCP/IP. The software is called Netguard and is located here.

See the project task below to install and operate Netguard.

Required reading

Orfali, Robert, Harkey, Dan and Edwards, Jeri (1996) The essential client/server survival guide (2nd. ed.), John Wiley & Sons Inc. pp. 675. Read about the web standards in chapters 33.

Exercises

Module 3, Topic 9 Network security

Aims

The aim of information security is to achieve confidentiality, integrity and availability. In this topic, we will study the special, Internet related threats to security and the counter measures. The student will gain:-

Syllabus

1. Internet and Intranet specific threats
2. Some protocols at risk
3. Public key cryptography
4. X.509 certificates and SSL
5. Security service suppliers and security software

1. Internet and Intranet specific threats

The student may wish to revise the security part of topic 3.

Internet security tries to defend against two distinct threats by achieving access security and transaction security.

Access security refers to a corporation's ability to protect its computers, memory, disk, printers and other computing equipment from unauthorised use. Firewalls are used to restrict access.

Cisco is a major provider of routers, devices used to connect networks to the Internet, so obviously Cisco's packet filter strategies are essential reading.

Transaction security or communications security refers to the ability of two entities on the Internet to conduct a transaction privately, and with authentication and digital signatures if required. Electronic commerce on the Internet and the Web fundamentally depends on transaction security. Secure HTTP and SSL are mechanisms for transaction security on the World Wide Web.

The following are essential reading for those interested in Internet security strategies.

• Microsoft Internet Security Framework
• Netscape On Internet Security

2. Some protocols at risk and counter measures

2.1 Secure telnet

Telnet is used to gain remote access to main frame computers, often controlled by a user name and a password, eavesdropping in public networks makes such protocols very insecure.

Secure versions of telnet like protocols aim to remove the need to pass passwords over the network or to exchange passwords in scrambled form using cryptographic methods. If cryptography is used to protect passwords, it can then be used to scramble the whole session.

Secure telnet and other TCP/IP sockets with Datafellows SSH

2.2 Privacy enhanced email

Email is passed around the Internet in a store and forward manner. Hence the methods for secure telnet, involving two computers in real time, online connections, can not be used to secure email.

There are RFCs for Privacy Enhanced Mail (PEM), the HTTP based Secure Socket Layer protocols and tools are used for Secure Multimedia Internet Mail (S-MIME), the most used tool for secure email is neither of these, it is Pretty Good Privacy (PGP).

With PGP, email is scrambled and a public key system is used to spread a network of trusted public keys.

Pretty Good Privacy Inc.

2.3 Secure http

Secure Socket Layers (SSL) is the most frequently used security protocol for the web. This prevents servers fraudulently claiming and identity to collect say VISA card numbers. SSL also enables scrambling of the information sent to clients, so preventing eavesdroppers from getting private or valuable information without authority.

SSL is described in our text book Orfali et. al. p. 501 - 505.

2.4 Client/User authentication

SSL and client certificates can be used to enable clients to authenticate their rights of access.

2.5 Secure funds transfer (SET)

Secure electronic transactions (secure electronic funds transfer) (SET) is not yet a stable technology. there are obvious dangers of forgery, theft, fraud due to the security holes of authenticity and confidentiality inherent in large public networks like the Internet.

Microsoft is leading a consortium to try to solve these problem, see Microsoft Internet Security Framework.

3. Public key cryptography

The technical tools used to scramble data is often public key cryptography. In the USA, Public Key Cryptography has been patented. The patents are held by RSA DSI Inc. They have a fine FAQ on public key cryptography and the RSA system, the most commonly used.

4. X.509 certificates and SSL

In order to use public key cryptography and the RSA algorithm for confidentiality and authentication, there is a need to distribute public keys. This is done by digitally signed certificates. X.509 is an ITU-T (CCITT) standard for certificates and is used in the SSL protocol. X.509 certificates can be used for both client and server authentication. The demonstration (DEMO) at X.509.com is an excellent tutorial. Set aside 30 minutes and work through the whole demonstration with your Netscape Navigator version 2.02 or later or Microsoft Internet Explorer version 3 or later.

5. Security service suppliers and security software

Here are some web security service and software sources:

• RSA Data Security Inc.
• X509.com a web security software provider
• Secure telnet and other TCP/IP sockets with Datafellows SSH
• Apache WWW server and Apache-SSL secure server
• Test your viewer does it support P.I.C.S. ratting labels? RSACi is the Recreational Software Advisory Council, they rate web sites
• SSLeay Certificate Authority FAQ and how to be a CA
• Pretty Good Privacy Inc.

Required reading

Orfali, Robert, Harkey, Dan and Edwards, Jeri (1996) The essential client/server survival guide (2nd. ed.), John Wiley & Sons Inc; see Secure Socket Layer (SSL) pp. 501 - 505 and packet filters pp. 507 - 508.

Udell, John (1996) Your business needs the web, in Byte, Volume 21, Number 8, August 1996, pp. 68-80.

Exercises

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