Novell Directory Services is a fully-replicated, globally distributed, object-oriented, hierarchical database of physical network objects. This type of hierarchical database implements a tree structure that is composed of a root segment, parent segments, and child segments. The segment is the equivalent of file’s record type. The hierarchical database model depicts a set of one-to-many (1:M) relationships between a parent and its children. The hierarchical model uses a hierarchic sequence or preorder traversal to navigate through its structures, always starting at the left side of the tree. Given its parent/child structure, the hierarchical model yields database integrity and consistency: There cannot be a child record without a parent. In addition, a well-designed hierarchical database is very efficient when handling large amounts of data or many transactions (Rob,Coronell, page44, Database Systems).

The NDS type of computing infrastructure stores information about all Internet, intranet, and network resources on a network (WebPages). NDS arranges network resources independently from their physical location (CNE 93). NDS provides network simplicity by representing any network resource such as faxes, routers, switches, printers on the network.. Software applications such as database and word processing functions as well as the volumes in the network file system are simplified by objects as well. The interaction and relationships between these objects can be controlled by the access control services of NDS. With simple drag and drop operation individual objects, groups of objects, or entire branches of the NDS tree can be moved to different locations (Website).


Resources, information and applications on intranets and the Internet are in constant fluctuation. NDS provides the ability to organize and classify this information so communication between users, vendors, customers and salespeople is effectively and safely managed (Website).

Logging onto several servers individually can be time consuming and inefficient as well as costly. NDS allows the user to logon to the network from a single point with only one password.

NDS Properties and attributes: NetWare 5 page 150 2nd paragraph 154

A network administrators primary responsibilities include maintaining the servers, volumes, users, groups, printers, and other resources in the network. NDS enables you to view all network resources as objects within a distributed or networkwide name service known as the NDS tree. A decision as to how resources are created and placed as objects in the name service must be made by the administrator.

How NDS works:

NDS is made up of objects and properties that are defined by a set of rules in the Directory call a schema. These schema rules dictate the naming and relationship of the objects and properties that can exist in the Directory. The schema consists of three main components called the object class, the property definitions, and the property syntax’s. Working together, these components establish the rules that control the creation of a particular object type in the Directory.

The concept of naming is closely tied to the NDS structure. Object naming is fundamental to the Directory because it provides a definition of the objects in the tree as well as their relationships to the other objects in the directory tree. Resource searching, a key function of the NDS name service, is provided through the use of object naming within the Directory. Good naming implies improved search capabilities now and in the future as more applications take advantage NDS Qualities( NetWare 4.1 networks).

Users, groups, printers, servers, volumes, and computers are the types of objects implemented.

NDS Limitations

Novell may have outsmarted itself by promoting NDS while waiting for Windows 2000 to come out. The changes in NDS are more evolutionary than revolutionary and therefore may be interpreted as "nothing new" according to Garret Hayes, a systems controls manager at Client/Server Labs. Inc. in Atlanta, a primary test lab partner for Computerworld. The biggest problem according to Hayes is that there are few if any "killer" applications already out there which make use of any directory services concept. This puts Novell in the difficult position of being to good to early. The opposite side to this it is that NDS is here and can be used right now while its difficult to tell exactly when Windows 2000 will be available.

Microsoft over the past few years has been waging a cold war

using propaganda and promises to slander Novell. This campaign involves directories that in theory let you find anything attached to the network such users, servers, and printers. A directory also allows you to manage all these resources from a single point especially when they share computers and move among PC’s.

Novell is winning this war because it can deliver the mentioned above right now. Microsoft has been promoting a new Active Directory that is now well overdue while customers wait for a centralized directory, new directory enabled applications, and scalable e-commerce. Novell finds itself on the verge of victory due to a strategy that returned it to the glory days. Sold under the Netware brand name was a product that allowed file and print sharing over a network. This was a service that Microsoft did not provide.

When Microsoft countered with the Windows NT product that is

extremely more capable, Novell got its ass kicked. Novell now finds itself on the verge of reversing this trend permanently. It has separated NDS from NetWare and has built NT and Unix versions. NDS for Linux (Linux is a flavor of Unix) was given a pubic demonstration at Brain share ‘99 in Utah.

The NDS for telecomms and Internet Service Providers will

standardize NDS. Once this happens there will be little reason to go with Microsoft’s Active Directory.

How NDS has provided company solutions:

"Tradition...with a Vision." Saint Andrew’s School in Boca Raton,

Florida, has both. First, is a 35 year history of providing excellence in education of mind, body, and spirit. Second is a view to cutting edge that combines technology and teaching at Saint Andrew’s School today, and which will become a reality for other schools.

Saint Andrew’s, an independent Episcopal school, offers a comprehensive educational curriculum to 660 students in grades 6-12, including 80 boarding students from 22 countries. The school is best known for providing an excellent education in a nurturing environment exemplified by small class sizes and student/teacher ratios often falling below 10/1.

All file servers at Saint Andrew’s School are now connected to a central switch via fiber optics which provide the primary avenue for teachers and students to exchange and obtain information. A high bandwidth T1 line links the school’s central network switch to the internet, installed in 1995 during phase two of the technology program, making Saint Andrew’s the first secondary school in the country to accomplish this. The school also configured every computer on campus to search the internet and make high-speed data transfers and file downloads available to all students and teachers. At internet workshops with 60 simultaneous users, surfers haven’t noticed degraded response or performance. Kenyon observes, "The structure of the school, any school where similar security challenges exist with children, and where students are moving about and sitting at different places in different times, was a clear match for the Novell network. We centrally manage 6 new Novell File Servers with Novell Directory Services (NDS), which offers different levels of security for teachers, students, and administrators. The architecture enables us to serve the various functional needs of our ‘customers,’ that is student, teacher, and administrator users."


Results To Date

Kenyon believes the computer network has radically changed some of the fundamental educational processes at Saint Andrew’s School. For example, all Saint Andrew’s students have individual E-mail addresses and regularly use E-mail to complete cross-curricular assignments in disciplines ranging from science to the arts. As such, they hone writing, research, and problem solving skills essential for future college work. Practice with tools-of-the-trade builds high levels of confidence and capability in students. http://www.novell.com/showcase/standrews.html ABN AMRO Bank, headquartered in Amsterdam, is the 14th largest bank worldwide based on total assets. With more than 1600 branches in 69 countries, ABN AMRO Bank has a strong local presence in major markets throughout the world.

Supporting the treasury operations of the bank is the Capital Markets Group, located in ABN AMRO’s North American headquarters in Chicago. The Capital Market Group’s network consists of 35 Novell NetWare servers connected to 1200 workstations, and is serviced by the ABN AMRO Information Technology Services Group.


Challenge In 1995, the Capital Markets Group decided to make the transition from Novell NetWare 3.12 to NetWare 4.1. In addition to their Master License Agreement, the Information Technology Services Group chose to purchase the services of a Novell Primary Support Engineer (PSE). Because the treasury operations include handling currency trades and other time sensitive transactions, keeping the Capital Markets Group’s system up and running is critical to the bank’s function. Anytime a problem arises, the Novell PSE is ready to provide immediate support.


The Novell Solution When the Information Technology Services Group ran into some trouble with NetWare Directory Services (NDS), they were able to send the NDS data directly to their Primary Support Engineer at Novell for troubleshooting. Faced with such a problem from his client, the PSE literally walked down the hall and discussed it with the programmer who had actually written the NDS code. Resolving issues this way takes very little time.


Challenge Kevin Higgs once was a testing engineer for a large aerospace company, but he found the perfect inner-space launch vehicle after he went to work for the State of Utah. Utah’s rate of growth rivals that of any state in the nation, but the state government’s budget isn’t keeping pace. That’s the reason Higgs and his fellow computer professionals use advanced Novell software technologies to save time and money while improving productivity and government service—it’s all about doing more with less. A CNE nearing completion of courses to become an MCNE, Higgs is a LAN administrator within the Utah executive branch. His immediate needs calls for support of four IntranetWare servers and 125 users in the Governor’s Office of Planning and Budget., but that is the tip of the IntranetWare iceberg for Higgs. Adding the IntranetWare and NetWare-linked servers in the counties runs the total smoothly operating network to more than 1,000 servers.


The Novell Solution One of Higgs’ favorite efficiency tools is the Novell Application Launcher™ (NAL). "We run virtually everything through NAL," he says. The tool allows Higgs to stay at his work site yet accomplish things that once required travel—and took a lot more time. "Let’s say staff at the Governor’s Mansion needs to prepare a presentation, but they don’t have the software they need," he explains. "As an administrator, with a few clicks of the mouse I can give them rights to the application and deliver it to their workstation." Using Novell Directory Services as a central repository for application and user data, NAL lets you create standard desktop configurations for different user groups to ensure that current—and future—people in a group automatically get the resources they need. Since NAL-delivered applications are linked to a user’s login ID, people always have access to their applications from any workstation on the network or from remote or mobile clients.


Results To Date Just as NAL makes it easier to get the right applications and tools to the people who need them, NDS simplifies management and administration of the entire network infrastructure. NDS is a distributed computing infrastructure that stores information about all Internet, intranet, and network resources to provide comprehensive, secure access to and management of all resources. It maintains information about every resource on the network—including users, groups, printers, volumes, network devices, and any other customizable object—in a hierarchical tree structure. NDS enables users and network supervisors to log in once, using one password, and be authenticated to the entire network, instead of logging into each file server and other network resources separately. Because it’s network-centric rather than server-centric, NDS presents users with a simple, logical view of all network resources to which they have rights. "IntranetWare handles our telecommuters flawlessly. It would be difficult to quantify the enhanced productivity we get from IntranetWare and NAL. The walking and driving we don’t have to do and the calls we don’t have to make are so frequent that we tend to take the software for granted."


Changes to NDS in Netware 5:

NDS has been modified to make it more secure, manageable, flexible and scalable. Transitive synchronization, transitive vector, replica change caching, multiple objects per packet, randomized replica lists, distributive and WAN Traffic Manager. Role based administration using the inheritable ACL’s or the password property.

Replica synchronization process in NetWare 5 uses transitive synchronization, which is the method of using transitive vectors while synchronizing two NetWare 5 servers. The transitive vector replaces the synchronized up to property that was used in NetWare 4.

With NetWare 5, replication no longer happens within a replica ring or list. The transitive server implements time synchronization. If a source server’s transitive vector is more recent than a target server’s vector, the source server does not need to synchronize with that target server. Synchronization traffic is thereby reduced, freeing up bandwidth. It uses either the IPX or IP protocol.

The transitive vector is a new structure that has been added to the partition on root

It’s actually a group of modification timestamps representing the values held by each replica.. One transitive vector is used for each replica. The synchronized up to property is different from the transitive vector in that it holds up to one value for each replica in the partition. Another major difference is that transitive vectoring is synchronized between servers.

A specific server does not have to contact each of the other servers in the partition to complete the replica sychronization process.

In NetWare 4, when the replica synchronization starts, it contacts and updates each of the replicas in the replica ring in sequential order. Therefore, the first replica in the replica ring is updated first, followed by the second one, and so on. Since the replica

Is updated first, followed by the second one, and so on. Since the replica ring is identical on all the servers holding copies of this partition, the synchronization process updates all the replicas for each partition in the same order. The effect of this may be undesirable if multiple servers are trying synchronize with the same replica on the same server simultaneously. Since only on inbound synchronization is supported per partition (not per server), one of the sychronizaiton processes will have to back off and make the attempt again at a latter time. This situation only arises if the synchronization process tends to execute at approximately the same time on multiple servers.

To help solve this problem, NetWare 5 changes the sequence in which replicas are processed by randomizing the replica ring list before attempting to contact the server. This greatly reduces the chances that one of the servers will have to back off and attempt to resynchronize with a replica. By randomizing which replica receives the first update, transitive synchronization will more quickly converge the data for each partition.

Cache object changes to the NDS objects enhances the performance of the replica synchronization process.