Glossário de SS7 e SIGTRAN

• Ver também Mensagens do ISUP

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.