The SDM communicates with headend devices using SNMP (Simple Network Management Protocol), an Internet standard protocol for managing devices on IP networks. All SNMP read and write requests to a device are accompanied by an SNMP community string, which can be thought of as a password. Permissions are associated with a community string, so that the device can grant an appropriate level of access to the requester. In the context of the SDM, the access levels typically supported are:
- read-only
- read-write
Most legacy headend devices that are supported by the SDM have typically used community strings that are common in the computing industry, and which provide minimal levels of security. Newer ARRIS devices have begun to support community strings which are more secure by default, and which are customizable by the operator for even greater security.
To support these newer device releases, with SDM Release 5.6 (and later), the SDM allows the user to configure the community strings used by the SDM.
Refer to Community Strings for Device Discovery and SNMP Community String Parameters for additional information.