ject tree. Each entity to be managed needs to be uniquely identified using a name, num- ber, or a combination of the two, known as an Object Identifier. The object is a part of the tree, its identity is defined using the traversal path starting at the Root and ending at the object position. The starting point in an object tree is always the Root. Below the root are identifiers for standardizing bodies CCITT and ISO, along with these is an identifier for joint definitions of CCITT and ISO. ISO has four children namely standard, registration authority, member body, and organization with iden- tifier values 0, 1, 2, and 3, respectively. Example of value assignments for an object identifier: 1. management OBJECT IDENTIFIER ::= { internet 2 } // name-number combination 2. internet OBJECT IDENTIFIER ::= { iso(1) org(3) dod(6) 1 } // name-number combination 3. internet OBJECT IDENTIFIER ::= {1361} // identification using number alone Information Handling There can be scenarios where the object descriptor will not be unique, but the combination of object descriptor and object identifier will always be unique globally. 15.2.2 ASN.1 Structured Type In this section we will look into four ASN.1 structured types. They are: SEQUENCE: Used for collection of variables of different type (can have a few variables of the same type but all variables are not of same type) where order is significant. Type Definition: NodeInfo : = SEQUENCE { nodeName VisibleString, nodeState VisibleString, BladeNo INTEGER Value Assignment: MediaGateway NodeInfo : = nodeName "MGW-10" nodeState "Offline", BladeNo 4 SEQUENCE OF: Used for collection of variables of same type where order is significant. Type Definition: UserList : = SEQUENCE OF VisibleString Value Assignment: operators UserList : = { "Joe" "Patrick", "Dan" "Peter", SET: Used for collection of variables of different type (can have a few vari- ables of same type but all variables are not of same type) where order is insig- nificant. Tagging of items in the set is required to uniquely identify