White Paper Z500a
for more challenging tasks such remote problem solving and correction. In addition, DM may be one of the tools used for remote firmware updates.
DM Tree
The settings that can be configured via OMA DM must be specified in a DM tree which is a data structure with which the DM client communicates settings to the host device. The tree is made up of nodes (sometimes called management objects) that can be modified by the client. In the future, it will be possible to include nodes that support the installation and removal of software applications in devices with open operating systems. The DM tree for the Z500a includes, among other things, the
settings that are necessary for WAP. These settings should be customized in the factory but can be updated by the service provider. This could prove to be extremely useful for infrastructure modifications including the modifications needed when service providers merge or increase capacity. A standardized way of dealing with these changes allows for a more efficient transition for a variety of devices from multiple vendors.
Nodes
Nodes are entities that can be manipulated by the client as commanded via the OMA DM protocol. The protocol supports nodes as simple as integers and more complex than GPRS data accounts. An interior node in the tree can have a large number of child nodes. The number is only limited by the amount of memory available. Each note has a unique URI. In addition, nodes have an
associated Access Control List (ACL) that is a list of servers that are given permission to manipulate the node. The servers are identified by a unique
Security
A powerful tool like OMA DM requires powerful security mechanisms. OMA DM uses Message Digest 5 (MD5) authentication. Either the client or the server may challenge for authentication. Integrity is handled with a Hashed Message Authentication Code (HMAC). User of the HMAC is optional. There are two aspects of confidentiality for OMA DM. Confidentiality of information during transport is handled by the transport protocol. TLS and HTTPS could be utilized. The other aspect of confidentiality is confidentiality between DM servers. This is handled by the ACL mentioned previously. Nodes in the DM tree cannot be modified by servers not included in the ACL.
24 | June 2004 |