This is where any l2/l3/l4 match criteria would be described.

CreateRequest contains the list of interfaces to be Qualified.
Each interface must only appear once and all IDs to be used
by qualification must be unique on the device.

CreateResponse will return a map of the status of each CreateRequest.
The map key is the qualification id requested in the CreateRequest.
Valid Status responses are:
OK: create has been accepted.
NOT_FOUND: interface_name could not be found on the service.
INVALID_ARGUMENT: if any of the configuration is not supported.
ALREADY_EXISTS: if the qualification id is already in use.

DeleteRequest will delete the qualification results for the provided id.

Delete response will contain a list of all id's in the request to be deleted.
If the id was not found NOT_FOUND will be returned.

If the service does not support any of the defined
modes then the message should be unset.

GetRequest returns the status for the provided ids.

GetResponse returns a map containing the values for all requested
Qualification results. If the QualificationResult state is
QUALIFICATION_STATE_ERROR the caller should inspect the status field for
the exact error code and message.
Expected errors codes:
NOT_FOUND when the requested id was not found by the service.
INVALID_ARGUMENT for any configuration parameter which is unsupported.

A packet generator implementation defines that the generator of the side of
the link will be responsible for generating a stream of packets at the
provided rate and size.

A packet injector implementation defines that the generator side of the link
will be responsible for both setting the interface into a loopback as well
as injecting individual packets up to packet_count into the closed loop at
the packet_size. These packets will form a closed loop as both sides of the
loop will forward the same set of packets for the duration of the
qualification.

PMD or port based loopbacks are expect to have limited ability
to report packet counters. Packet rate/errors/transmitted/received
may not be available on the remote side for these types of loopbacks.

RPCSyncedTiming will be all synchronization by assuming the start rpc's are
sent very close temporally with enough overlap in duration to get valid
results.
The pre_qual_wait will allow the caller to adjust any setup timing
differences between peers. The post_qual_wait will allow for the caller to
adjust any teardown differences in timing between peers.
pre_qual_wait cannot be less than selected endpoint type's min_setup_time.
post_qual_wait cannot be less than the selected endpoint type's
min_teardown_time.

If the service does not support any of the defined
modes then the message should be unset.

States of qualification.

A Duration represents a signed, fixed-length span of time represented
as a count of seconds and fractions of seconds at nanosecond
resolution. It is independent of any calendar and concepts like "day"
or "month". It is related to Timestamp in that the difference between
two Timestamp values is a Duration and it can be added or subtracted
from a Timestamp. Range is approximately +-10,000 years.

# Examples

Example 1: Compute Duration from two Timestamps in pseudo code.

Timestamp start = ...;
Timestamp end = ...;
Duration duration = ...;

duration.seconds = end.seconds - start.seconds;
duration.nanos = end.nanos - start.nanos;

if (duration.seconds < 0 && duration.nanos > 0) {
duration.seconds += 1;
duration.nanos -= 1000000000;
} else if (duration.seconds > 0 && duration.nanos < 0) {
duration.seconds -= 1;
duration.nanos += 1000000000;
}

Example 2: Compute Timestamp from Timestamp + Duration in pseudo code.

Timestamp start = ...;
Duration duration = ...;
Timestamp end = ...;

end.seconds = start.seconds + duration.seconds;
end.nanos = start.nanos + duration.nanos;

if (end.nanos < 0) {
end.seconds -= 1;
end.nanos += 1000000000;
} else if (end.nanos >= 1000000000) {
end.seconds += 1;
end.nanos -= 1000000000;
}

Example 3: Compute Duration from datetime.timedelta in Python.

td = datetime.timedelta(days=3, minutes=10)
duration = Duration()
duration.FromTimedelta(td)

# JSON Mapping

In JSON format, the Duration type is encoded as a string rather than an
object, where the string ends in the suffix "s" (indicating seconds) and
is preceded by the number of seconds, with nanoseconds expressed as
fractional seconds. For example, 3 seconds with 0 nanoseconds should be
encoded in JSON format as "3s", while 3 seconds and 1 nanosecond should
be expressed in JSON format as "3.000000001s", and 3 seconds and 1
microsecond should be expressed in JSON format as "3.000001s".

A Timestamp represents a point in time independent of any time zone or local
calendar, encoded as a count of seconds and fractions of seconds at
nanosecond resolution. The count is relative to an epoch at UTC midnight on
January 1, 1970, in the proleptic Gregorian calendar which extends the
Gregorian calendar backwards to year one.

All minutes are 60 seconds long. Leap seconds are "smeared" so that no leap
second table is needed for interpretation, using a [24-hour linear
smear](https://developers.google.com/time/smear).

The range is from 0001-01-01T00:00:00Z to 9999-12-31T23:59:59.999999999Z. By
restricting to that range, we ensure that we can convert to and from [RFC
3339](https://www.ietf.org/rfc/rfc3339.txt) date strings.

# Examples

Example 1: Compute Timestamp from POSIX `time()`.

Timestamp timestamp;
timestamp.set_seconds(time(NULL));
timestamp.set_nanos(0);

Example 2: Compute Timestamp from POSIX `gettimeofday()`.

struct timeval tv;
gettimeofday(&tv, NULL);

Timestamp timestamp;
timestamp.set_seconds(tv.tv_sec);
timestamp.set_nanos(tv.tv_usec * 1000);

Example 3: Compute Timestamp from Win32 `GetSystemTimeAsFileTime()`.

FILETIME ft;
GetSystemTimeAsFileTime(&ft);
UINT64 ticks = (((UINT64)ft.dwHighDateTime) << 32) | ft.dwLowDateTime;

// A Windows tick is 100 nanoseconds. Windows epoch 1601-01-01T00:00:00Z
// is 11644473600 seconds before Unix epoch 1970-01-01T00:00:00Z.
Timestamp timestamp;
timestamp.set_seconds((INT64) ((ticks / 10000000) - 11644473600LL));
timestamp.set_nanos((INT32) ((ticks % 10000000) * 100));

Example 4: Compute Timestamp from Java `System.currentTimeMillis()`.

long millis = System.currentTimeMillis();

Timestamp timestamp = Timestamp.newBuilder().setSeconds(millis / 1000)
.setNanos((int) ((millis % 1000) * 1000000)).build();

Example 5: Compute Timestamp from Java `Instant.now()`.

Instant now = Instant.now();

Timestamp timestamp =
Timestamp.newBuilder().setSeconds(now.getEpochSecond())
.setNanos(now.getNano()).build();

Example 6: Compute Timestamp from current time in Python.

timestamp = Timestamp()
timestamp.GetCurrentTime()

# JSON Mapping

In JSON format, the Timestamp type is encoded as a string in the
[RFC 3339](https://www.ietf.org/rfc/rfc3339.txt) format. That is, the
format is "{year}-{month}-{day}T{hour}:{min}:{sec}[.{frac_sec}]Z"
where {year} is always expressed using four digits while {month}, {day},
{hour}, {min}, and {sec} are zero-padded to two digits each. The fractional
seconds, which can go up to 9 digits (i.e. up to 1 nanosecond resolution),
are optional. The "Z" suffix indicates the timezone ("UTC"); the timezone
is required. A proto3 JSON serializer should always use UTC (as indicated by
"Z") when printing the Timestamp type and a proto3 JSON parser should be
able to accept both UTC and other timezones (as indicated by an offset).

For example, "2017-01-15T01:30:15.01Z" encodes 15.01 seconds past
01:30 UTC on January 15, 2017.

In JavaScript, one can convert a Date object to this format using the
standard
[toISOString()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString)
method. In Python, a standard `datetime.datetime` object can be converted
to this format using
[`strftime`](https://docs.python.org/2/library/time.html#time.strftime) with
the time format spec '%Y-%m-%dT%H:%M:%S.%fZ'. Likewise, in Java, one can use
the Joda Time's [`ISODateTimeFormat.dateTime()`](
http://www.joda.org/joda-time/apidocs/org/joda/time/format/ISODateTimeFormat.html#dateTime%2D%2D
) to obtain a formatter capable of generating timestamps in this format.

The `Status` type defines a logical error model that is suitable for
different programming environments, including REST APIs and RPC APIs. It is
used by [gRPC](https://github.com/grpc). Each `Status` message contains
three pieces of data: error code, error message, and error details.

You can find out more about this error model and how to work with it in the
[API Design Guide](https://cloud.google.com/apis/design/errors).

Credentials defines credentials needed to perform authentication on a device.

HashType defines the valid hash methods for data verification. UNSPECIFIED
should be treated an error.

Path encodes a data tree path as a series of repeated strings, with
each element of the path representing a data tree node name and the
associated attributes.
Reference: gNMI Specification Section 2.2.2.

PathElem encodes an element of a gNMI path, along with any attributes (keys)
that may be associated with it.
Reference: gNMI Specification Section 2.2.2.

Generic Layer 3 Protocol enumeration.

The gNOI service semantic version.