Value Ranges and Limits

The following rules apply to object IDs in ASN.1 notation:

• The object ID consists of 1 to 128 subIDs, which are separated by dots.

• Each subID is a positive number. No negative numbers are allowed.

• The value of each number cannot exceed 4294967295 (4,294,967,295). This value is 2 to the power of 32 minus 1.

• The valid values of the first subID are: 0, 1, or 2.

• If the first subID has a value of 0 or 1, the second subID can only have a value of 0 through 39.

The following rules apply to DisplayString:

• A DisplayString (Textual Convention) is basically an OCTET STRING in SNMP terms.

• The maximum size of a DisplayString is 255 octets/bytes.

• The octets of a DisplayString must belong to the ASCII NVT character set. This character set is not precisely defined, but commonly accepted to consist of all ASCII characters with a value in the range of 0-127 inclusive.

  A further limitation is that the CR (hex 13) must always be followed by either a LF (hex 0A) or a NUL (hex 00).

More information on the DPI SNMP value types can be found in the SNMP SMI (Structure of Management Information) and SNMP TC (Textual Conventions) RFCs. At the time of this publication, these two RFCs are RFC1442 and RFC1443.