Glossário de SS7 e SIGTRAN

AERM Alignment Error Rate Monitor

ARP Address Resolution Protocol (RFC 826)

AS Application Server

Term used in SIGTRAN to describe an application which runs in an IPSP and which is addressed using either a DPC/OPC or SIO/DPC/OPC (if using SCCP) and represents a Routing Key.

ASE Application Service Element

BIB Backward Indicator Bit

BICC Bearer Independent Call Control

BISUP Broadband ISDN User Part

Call set-up procedures for Broadband networks to deliver services such as HDTV, video-conferencing.

BSN Backward Sequence Number

BSSMAP Base Station system Mobile Application Part

Procedures used from the Mobile Switching Center (MSC) to the Base Station Controller (BSC) in GSM networks.

Call Control

Call Control is the generic term used to describe messages which are concerned with establishing (call set-up) or terminating (call tear-down) a connection on a Circuit Switched Network (CSN).

CAMEL Customised Applications for Mobile networks Enhanced Logic

defines a set of services used in GSM/3G networks. Messages are carried in the CAP SS7 protocol.

CAP CAMEL Application Part

is a subset of INAP and is carried in an extension of TCAP.

CCS Common Channel Signaling

CIC Circuit Identification Code

CSN Circuit Switched Network

Network in which a permanent end-to-end circuit is maintained from call establishement to call tear-down. Contrasted with packet networks.

DPC Destination Point Code

is carried in the Routing Label and indicates the Point Code to which the messages is addressed. It is used by MTP3 to address SS7 MSUs.

DUP Data User Part

EP End Point

is a term used in SS7 to describe a final destinations for MSUs addressed using Point Codes. Thus SSPs (which provide end-user services) and SCPs (which provide database services) are end points. STPs (which provide routing and other services) are not end points.

FCS Frame Check Sequence

FIB Forward Indicator Bit

FISU Fill-In Signal Unit

is one of three packet types that are used in a SS7 signaling network. The FISU is sent only when the SS7 network is idle and is used to monitor signal quality and network integrity. The other packet types are LSSU and MSU.

FSN Forward Sequence Number

GTT Global Title Translation

HLR Home Location Register

Term used in mobile networks to describe the system which contains information abouta mobile subscriber such as subscribed services, billing information and current location. If the subscriber is currently roaming there will be a copy of some of this information in the VLR of the roaming network.

ICMP Internet Control Message Protocol (RFC 792)

INAP Intelligent Network Application Part

Advanced Signalling associated with Intelligent Network (IN) (RoW) or Advanced Intelligent Network (AIN) (US).

IP Internet Protocol (RFC 753, RFC 759, RFC 766, RFC 774, RFC 791...)

IPSP An IP Signalling Point

is defined by SIGTRAN (an IETF protocol) to be an SS7 end-point in a IP network and which runs one or more AS.

ISP Intermediate Service Part

ISPC International Signaling Point Code

ISUP ISDN User Part

is a Call Control protocol used in establishing (call set-up) or terminating (call tear-down) a connection on a Circuit Switched Network (CSN). Other call control protocols are TUP, BISUP and national variants such as IUP and NUP.

IUP Interconnect User Part

is a UK Call Control protocol used in establishing (call set-up) or terminating (call tear-down) a connection on a Circuit Switched Network (CSN). Other call control protocols are TUP, BISUP, ISUP and national variants such as NUP.

LI Length Indicator

LSSU Link Status Signal Unit

is one of three packet types that are used in a SS7 signaling network. The LSSU is to send information about link status between end-points. The other packet types are FISU and MSU.

M2PA MTP2 Peer-to-Peer Adapter (IETF draft v6)

is part of SIGTRAN and is an IETF protocol that allows SS7 MTP3 messages to be transferred to an IP network. M2PA by preserving the MTP3 layer each end-point in the IP network to have a Point code.

M2UA

M2UA is part of SIGTRAN and is an IETF protocol that allows SS7 MTP3 messages to be relayed to an IPSP. The Signaling Gateway (SG) acts tranparently and does not need a point code.

M3UA MTP3 User Adapter (RFC 3332)

is part of SIGTRAN (an IETF protocol) that allows SS7 MTP3 messages to be used by the Signaling Gateway (SG) to select multiple IPSP destinations based on criteria defined to the M3UA layer and without the need for additional point codes.

MAC Media Access Control

MAP Mobile Application Part

The pre-3G term used to define procedures used in mobile networks such as roaming. Sits on top of TCAP.

MGC Media Gateway Controller

Generic term which describes any system that converts from one media or network type to another such as a VoIP gateway.

MSU Message Signal Unit

is one of three packet types that are used in a SS7 signaling network. The MSU carries User Part protocol messages. The other packet types are LSSU and FISU.

MTP Message Transfer Part

Generic term covering layer MTP3, MTP2 and MTP1.

MTP1 Message Transfer Part 1

The physical layer concerned with placing data onto, and reading from, a single (point-to-point) network connection.

MTP2 Message Transfer Part 2

Data Link Layer - concerned with ensure reliable communication between both ends of a single (point-to-point) network connection.

MTP3 Message Transfer Part 3

Network layer - concerned with moving data between end points in the network. The end-point address (point code) is visible to MTP3.

NACK Negative acknowledgement

NIF Nodal Inter-working Function

is a term used in SIGTRAN (an IETF protocol) to describe a glue layer that interfaces various layers within the SS7 or SIGTRAN stacks. The functionality of the NIF is not defined within the standard and is therefore implementation specific.

NSP Network Services Part

NUP Network User Part

is a UK Call Control protocol used in establishing (call set-up) or terminating (call tear-down) a connection on a Circuit Switched Network (CSN). Other call control protocols are TUP, BISUP, ISUP and national variants such as IUP.

OMAP Operations and Maintenance Application Part

OPC Origination Point Code

is carried in the Routing Label and indicated the Point Code that originated the messages. It is used by MTP3 to address SS7 MSUs.

OSI Open Systems Interconnection

PC Point code

is the address of an end-point in a SS7 network (or a SIGTRAN enhanced service). The ITU-standard uses 14 bits, ANSI (North America) uses a 24 bit code (network, cluster, member octets).

RANAP Radio Access Network User Part

Term used by 3G and defines communication between the Mobile equipement (ME) and the Radio Network Controller (RNC) and the Mobile Switching Center (MSC). Roughly equivalent to BSSMAP in pre-3G (GSM) networks.

Routing Key

is a term used in SIGTRAN and defines the SS7 message parameters, such as DPC or SIO (or combinations) that will be handled by a specific AS (IPSP. Essentially it defines the SS7 to IP address mapping for a specific function (SIO) or address (DPC) and may be reagrded as a routing element within a routing table.

Routing Label

is used by MTP3 to address SS7 MSUs and consists of the DPC and OPC.

SAAL Signaling ATM Adaptation Layer

SANC Signaling Area Network Code

SCCP Signaling Connection Control Part

is carried in MSUs and allows for routing to applications based on one or more of the Point Code, subsystem number or called/in calling party number. SCCP supports and number of services such as TCAP, MAP, RANAP, INAP.

SCP Service Control Point

is End Point in a Common Channel Signaling System #7 SS7) network that provides a service such as credit card calling and typically but not exclusively requires database lookup. SS7 networks consist of SCPs, STPs and SSPs.

SCTP Stream Control Transport Protocol (RFC 2960, RFC 3309...)

is used by SIGTRAN (an IETF protocol) to reliably transport SS7 messages in an IP network from a Signaling Gateway (SG) to an IPSP. Adaption layers (M2PA, M2UA, M3UA and SUA) use the SCTP as a transport service.

SEP Signaling End Point

SF Status Field

SG Signaling Gateway

is part of SIGTRAN (an IETF protocol) and defines a system that converts from the SS7 network to the IP network. SGs use a common IP and SCTP base and adaption layers (M2PA, M2UA, M3UA and SUA).

SI Service Indicator

SIF Signaling Information

SIGTRAN Signal Transport

is an IETF protocol that allows SS7 messages to be reliably transported over an IP network using a common IP and SCTP base and adaption layers (M2PA, M2UA, M3UA and SUA).

SIO Service Information Octet

is used by MTP3 and indicates the higher level protcol being carried such as ISUP or TCAP and is used to route the MSU.

SLC Signal Link Code

SLS Signalling Link Selection code

SNM Signaling Network Management

SNT Signaling Network Testing

SP Signaling Point

SPC Signaling Point Code

SPR Signaling Point W/SCCP Relay function

SS7 Common Channel Signaling System #7

more commonly abbreviated to Signaling System 7 (SS7) is an out-of-band, packet-like network used to send messages to end-points in a telecommunications network, examples of such messages may be Call Control (using ISUP or application requests such as TCAP. SS7 networks consist of SSPs, STPs and SCPs.

SSF Sub-Service Field

SSN Subsystem Number (SSN)

is used by SCCP to identify the subsystem (application) for which the message is destined for example a specific database or system such as a HLR.

SSP Service Switching Point (SSP)

is an End Point in a SS7 network that provides end user services such as call set-up and tear-down. SS7 networks consist of SSPs, STPs and SCPs.

STP Signaling Transfer Point (STP)

provides intelligent routing and management features between various End-Points such as SSPs and SCPs.

SU Signal Unit

SUA SCCP User Adaption

is part of SIGTRAN and is an IETF adaption layer protocol that allows SS7 SCCP messages to be IP aware.

SUA SCCP User Adapter (IETF draft v3)

SUERM Signal Unit Error Rate Monitor

TALI Transport Adapter Layer Interface (RFC 3094)

TC Transaction Capabilities

TCAP Transaction Capability Application Part

Protocol layer that sits on top of SCCP. In turn TCAP carries higher level protocols such as RANAP, MAP etc.

TCP Transmission Control Protocol (RFC 675, RFC 793, RFC1347...)

TUP Telephony User Part

Older version of call control procedures concerned only with analog telephony. Not widely used, ISUP is more common since it offers more extensive services.

UP User Part

is the collective term given to all information carried above the Message Transfer Part (MTP).

VLR Visitor Location Register

Term used in mobile networks to describe a system which contains information about a mobile subscriber who is currently roaming in this network. The VLR obtains information (using MAP) from the subscribers HLR.

ISUP Message

Address Complete Message (ACM)

A message sent in the backward direction indicating that all the address signals required for routeing the call to the called party have been received.

Answer message (ANM)

A message sent in the backward direction indicating that the call has been answered. In semi-automatic working, this message has a supervisory function. In automatic working, this message is used in conjunction with charging information in order to: start metering the charge to the calling subscriber (see Recommendation Q.28 [2]); and start measurement of call duration for international accounting purposes (see Recommendation E.260 [3]).

Application Transport message (APM)

A message sent in either direction to convey application information using the Application Transport mechanism.

Blocking message (BLO)

A message sent only for maintenance purposes to the exchange at the other end of a circuit, to cause an engaged condition of that circuit for subsequent calls outgoing from that exchange. When a circuit is used in the bothway mode of operation, an exchange receiving the blocking message must be capable of accepting incoming calls on the concerned circuit unless it has also sent a blocking message. Under certain conditions, a blocking message is also a proper response to a reset circuit message.

Blocking Acknowledgement message (BLA)

A message sent in response to a blocking message indicating that the circuit has been blocked.

Call Progress message (CPG)

A message, sent in either direction during the setup or active phase of the call, indicating that an event, which is of significance, and should be relayed to the originating or terminating access, has occurred.

Charge information message (CRG)

Information sent in either direction for accounting and/or call charging purposes.

Circuit Group Blocking message (CGB)

A message sent to the exchange at the other end of an identified group of circuits to cause an engaged condition of this group of circuits for subsequent calls outgoing from that exchange. An exchange receiving a circuit group blocking message must be able to accept incoming calls on the group of blocked circuits unless it has also sent a blocking message. Under certain conditions, a circuit group blocking message is also a proper response to a reset circuit message.

Circuit Group Blocking Acknowledgement message (CGBA)

A message sent in response to a circuit group blocking message to indicate that the requested group of circuits has been blocked.

circuit Group Reset message (GRS)

A message sent to release an identified group of circuits when, due to memory mutilation or other causes, it is unknown whether for example, a release or release complete message is appropriate for each of the circuits in the group. If at the receiving end a circuit is remotely blocked, reception of this message should cause that condition to be removed.

circuit Group Reset Acknowledgement message (GRA)

A message sent in response to a circuit group reset message and indicating that the requested group of circuits has been reset. The message also indicates the maintenance blocking state of each circuit.

Circuit Group Unblocking message (CGU)

A message sent to the exchange at the other end of an identified group of circuits to cause cancellation in that group of circuits of an engaged condition invoked earlier by a blocking or circuit group blocking message.

Circuit Group Unblocking Acknowledgement message (CGUA)

A message sent in response to a circuit group unblocking message to indicate that the requested group of circuits has been unblocked.

Circuit group Query Message (CQM)

A message sent on a routine or demand basis to request the far-end exchange to give the state of all circuits in a particular range.

Circuit group Query Response message (CQR)

A message sent in response to a circuit group query message to indicate the state of all circuits in a particular range.

Confusion message (CFN)

A message sent in response to any message (other than a confusion message) if the exchange does not recognize the message or detects a part of the message as being unrecognized.

Connect message (CON)

A message sent in the backward direction indicating that all the address signals required for routeing the call to the called party have been received and that the call has been answered.

Continuity message (COT)

A message sent in the forward direction indicating whether or not there is continuity on the preceding circuit(s) as well as of the selected circuit to the following exchange, including verification of the communication path across the exchange with the specified degree of reliability.

Continuity Check Request message (CCR)

A message sent by an exchange for a circuit on which a continuity check is to be performed, to the exchange at the other end of the circuit, requesting continuity checking equipment to be attached.

Facility Accepted message (FAA)

A message sent in response to a facility request message indicating that the requested facility has been invoked.

Facility message (FAC)

A message sent in either direction at any phase of the call to request an action at another exchange. The message is also used to carry the results, error or rejection of a previously requested action.

Facility Reject message (FRJ)

A message sent in response to a facility request message to indicate that the facility request has been rejected.

Facility Request message (FAR)

A message sent from an exchange to another exchange to request activation of a facility.

Forward Transfer message (FOT)

A message sent in the forward direction on semi-automatic calls when the outgoing international exchange operator wants the help of an operator at the incoming international exchange. The message will normally serve to bring an assistance operator (see Recommendation Q.101 [4]) into the circuit if the call is automatically set up at the exchange. When the call is completed via an operator (incoming or delay operator) at the incoming international exchange, the message should preferably cause this operator to be recalled.

Identification Request message (IDR)

A message sent in the backward direction to request action regarding the malicious call identification supplementary service.

Identification Response message (IRS)

A message sent in response to the identification request message.

Information message (INF)

A message sent to convey information in association with a call, which may have been requested in an information request message.

Information Request message (INR)

A message sent by an exchange to request information in association with a call.

Initial Address message (IAM): A message sent in the forward direction to initiate seizure of an outgoing circuit and to transmit number and other information relating to the routeing and handling of a call.

Loop back Acknowledgement message (LPA)

A message sent in the backward direction in response to a continuity check request message indicating that a loop (or transceiver in the case of a 2-wire circuit) has been connected.

Loop Prevention message (LOP)

A message sent to convey information required by the ECT supplementary service.

Network Resource Management message (NRM)

A message sent in order to modify network resources associated with a certain call. The message is sent along an established path in any direction in any phase of the call.

Overload Message (OLM)

A message sent in the backward direction, on non-priority calls in response to an IAM, to invoke temporary trunk blocking of the circuit concerned when the exchange generating the message is subject to load control.

Pass-Along Message (PAM)

A message that may be sent in either direction to transfer information between two signalling points along the same signalling path as that used to establish a physical connection between those two points.

Pre-release Information message (PRI)

A message to be used with the Release message for the transport of information where sending of that information in the Release message itself would cause compatibility problems with ISUP 1992 and subsequent versions of the ISUP protocol.

Release message (REL)

A message sent in either direction to indicate that the circuit is being released due to the reason (cause) supplied and is ready to be put into the idle state on receipt of the release complete message. Where the call is to be redirected the message will also carry the redirection number.

Release Complete message (RLC)

A message sent in either direction in response to the receipt of a release message, or if appropriate to a reset circuit message, when the circuit concerned has been brought into the idle condition.

Reset Circuit message (RSC)

A message sent to release a circuit when, due to memory mutilation or other causes, it is unknown whether for example, a release or a release complete message is appropriate. If, at the receiving end, the circuit is remotely blocked, reception of this message should cause that condition to be removed.

Resume message (RES)

A message sent in either direction indicating that the calling or called party, after having been suspended, is reconnected.

Segmentation Message (SGM)

A message sent in either direction to convey an additional segment of an overlength message.

Subsequent Directory Number message (SDM)

A message that may be sent in the forward direction following an Initial Address Message, to convey additional called party number information, when the called party number in the Initial Address Message was contained in the Called Directory Number parameter.

Subsequent Address Message (SAM)

A message that may be sent in the forward direction following an initial address message, to convey additional called party number information.

Suspend message (SUS)

A message sent in either direction indicating that the calling or called party has been temporarily disconnected.

Unblocking message (UBL)

A message sent to the exchange at the other end of a circuit to cancel, in that exchange, the engaged condition of the circuit caused by a previously sent blocking or circuit group blocking message.

Unblocking Acknowledgement Message (UBA)

A message sent in response to an unblocking message indicating that the circuit has been unblocked.

Unequipped Circuit Identification Code message (UCIC)

A message sent from one exchange to another when it receives an unequipped circuit identification code.

User Part Available message (UPA)

A message sent in either direction as a response to a user part test message, to indicate that the user part is available.

User Part Test message (UPT)

A message sent in either direction to test the status of a user part marked as unavailable for a signalling point.

User-to-user information message (USR)

A message to be used for the transport of user-to-user signalling independent of call control messages.