Data Type Code

Description

SMIv1?

SMIv2?

Integer / Integer32

A 32-bit signed integer in two's complement notation, capable of holding a value from -2,147,483,648 to +2,147,483,647. Can also be used to represent an enumerated type; for example, where 1 represents a particular constant, 2 represents a different one, and so on.

Yes

Yes

Octet String

A variable-length string of binary or text data.

Yes

Yes

Null

Nothing.

Yes

—

Bits

An enumeration of named bits. Used to allow a set of bit flags to be treated as a single data type.

—

Yes

Unsigned

A 32-bit unsigned integer, from 0 to 4,294,967,295.

—

Yes

Network Address / IpAddress

An IP address, encoded as a 4-byte octet string.

Yes

Yes

Counter / Counter32

A 32-bit unsigned integer, that begins at 0 and increases up to 4,294,967,295, then wraps back to 0.

Yes

Yes

Gauge / Gauge32

A 32-bit unsigned integer, that may have a value from 0 to 4,294,967,295 and may increase or decrease, like a gauge. A minimum and maximum value are associated with the gauge, indicating its normal range.

Yes

Yes

TimeTicks

A 32-bit unsigned integer that indicates the number of hundredths of seconds since some arbitrary start date. Used for timestamping and to compute elapsed time.

Yes

Yes

Opaque

Data using arbitrary ASN.1 syntax that is to be passed between devices without being interpreted. As in NFS's XDR, the term “opaque” means that the data is treated like a “black box” whose internal details cannot be seen.

Yes

Yes

Counter64

A counter like Counter32 but 64 bits wide, allowing a value from 0 to 18,446,744,073,709,551,615.

—

Yes