1.1 Glossary

This document uses the following terms:

access point: A network access server (NAS) that is implementing [IEEE802.11-2012], connecting wireless devices to form a wireless network.

Authentication Protocol (AP) exchange: The Kerberos subprotocol called the "authentication protocol", sometimes referred to as the "Client/Server Authentication Exchange", in which the client presents a service ticket and an authenticator to a service to establish an authenticated communication session with the service (see [RFC4120] section 3.2).

basic service set identifier (BSSID): A 48-bit structure that is used to identify an entity such as the access point in a wireless network. This is typically a MAC address.

broadcast: The sending of a frame to the Ethernet broadcast domain by an LLTD-capable station.

charge: A mechanism used to prevent Denial of Service (DoS) attacks, as described in section 1.3.5.

controller: A station that initiates a network test request.

cross-traffic analysis: A technique used by Quality of Service (QoS) applications to understand the nature of network activity, usually resulting in the identification of the hosts that are responsible for most of this activity.

cross-traffic analysis initiator: A station that initiates a cross-traffic analysis request.

Current Transmit Credit (CTC): The charge available at a responder.

enumerator: A station that seeks all LLTD–capable stations on the link by using quick discovery.

error code: An integer that indicates success or failure. In Microsoft implementations, this is defined as a Windows error code. A zero value indicates success; a nonzero value indicates failure.

Ethernet broadcast domain: The portion of a network that can receive frames destined for the special broadcast MAC address (that is, consisting of all binary 1s).

flooding: A switch's sending of a frame to all segments to which it is connected. A switch will flood a frame containing a MAC address for which the switch does not know the corresponding segment.

friendly name: A name for a user or object that can be read and understood easily by a human.

generation number: A number used by a mapper to generate fresh MAC addresses from a private range.

hub: A data link-layer network device that acts as a shared bus. All stations that are connected to a hub are on the same segment; therefore, each station that is connected to a hub sees all frames that are sent to or from all other stations on that hub. Compare this term with router and switch.

interrupt moderation: The process of delaying central processing unit (CPU) interrupts generated by a local network interface. Delaying interrupts improves system efficiency by only generating a single interrupt for multiple events instead of an individual interrupt per event. Although desirable for improved system performance, delaying interrupts impacts the measurement accuracy of timed events. The algorithm determining the length of delay is hardware specific, therefore, not in scope of this specification.

mapper: A station that initiates a topology discovery test.

Media Access Control (MAC) address: A hardware address provided by the network interface vendor that uniquely identifies each interface on a physical network for communication with other interfaces, as specified in [IEEE802.3]. It is used by the media access control sublayer of the data link layer of a network connection.

network test: Generic term to describe any technique (for example, probegap or timed probe) that is used to estimate the throughput of a network.

probegap: A probing experiment that involves sending one or more probe packets from the initiator to the sink and then back to the initiator. The intention is to gather a series of one-way delay (OWD) samples. This technique is used to estimate the available bandwidth of the network path between the initiator and sink devices. Probegap is synergistic to timed probe and packet pair in the sense that the available bandwidth is calculated relative to the bottleneck bandwidth; the former cannot be calculated without knowing the latter. For an example of how probegap can be used by an application, see [ProbeGap].

Quality of Service (QoS): A set of technologies that do network traffic manipulation, such as packet marking and reshaping.

quick discovery: The process of discovering responders on a network.

real MAC address: A MAC address provided by the network interface vendor to uniquely identify the device on the network, as specified in [IEEE802.3].

RepeatBAND: A fast and scalable station enumeration algorithm as specified in section

responder: An LLTD–capable station to which mappers and enumerators send LLTD commands.

segment: A set of stations that see each other's link-layer frames without being changed by any device in the middle, such as a switch.

service set identifier (SSID): A sequence of characters that names a wireless local area network (WLAN).

session: A context for managing communication over LLTD among stations.

sink: A responder that is the target of a network test session.

station: Any device that implements LLTD.

switch: A data link-layer device that propagates frames between segments and allows communication among stations on different segments. Stations that are connected through a switch see only those frames destined for their segments. Compare this term with hub and router.

topology discovery test: A test that an application or higher-layer protocol can use to facilitate discovering the link-layer topology of a single link in a network. That is, to facilitate discovering the set of segments and switches, and determining which responders are on which segments. Compare this term with quick discovery.

type-length-value (TLV): A method of organizing data that involves a Type code (16-bit), a specified length of a Value field (16-bit), and the data in the Value field (variable).

UCS-2LE: A variation of the UCS-2 string encoding format. The specification of UCS-2 in [ISO/IEC-10646] represents each code point in big-endian format. In UCS-2LE, each code point is represented in little-endian format.

universally unique identifier (UUID): A 128-bit value. UUIDs can be used for multiple purposes, from tagging objects with an extremely short lifetime, to reliably identifying very persistent objects in cross-process communication such as client and server interfaces, manager entry-point vectors, and RPC objects. UUIDs are highly likely to be unique. UUIDs are also known as globally unique identifiers (GUIDs) and these terms are used interchangeably in the Microsoft protocol technical documents (TDs). Interchanging the usage of these terms does not imply or require a specific algorithm or mechanism to generate the UUID. Specifically, the use of this term does not imply or require that the algorithms described in [RFC4122] or [C706] must be used for generating the UUID.

wireless band: An IEEE 802.11 [IEEE802.11-2007] protocol family. For example, 802.11a is a wireless band.

MAY, SHOULD, MUST, SHOULD NOT, MUST NOT: These terms (in all caps) are used as defined in [RFC2119]. All statements of optional behavior use either MAY, SHOULD, or SHOULD NOT.