SS7 (七号信令)
Signaling System No. 7 (SS7) is a set (是一套而不是单一的协议) of telephony signaling protocols developed in 1975, which is used to set up and tear down most of the world’s public switched telephone network (PSTN) telephone calls. It also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other mass market services.
SS7 point code ( SPC )
An SS7 point code is similar to an IP address in an IP network. It is a unique address for a node (Signaling Point, or SP), used in MTP layer 3 to identify the destination of a message signal unit (MSU).
Signal Transfer Point ( STP )
A Signal Transfer Point (STP) is a router that relays SS7 messages between signaling end-points (SEPs) and other signaling transfer points (STPs). Typical SEPs include service switching points (SSPs) and service control points (SCPs). The STP is connected to adjacent SEPs and STPs via signaling links. Based on the address fields of the SS7 messages, the STP routes the messages to the appropriate outgoing signaling link. Edge STPs can also route based upon message body content using deep packet inspection techniques, and can provide address translations and screen content to limit the transfer of messages with dubious content or sent from unreliable sources. To meet stringent reliability requirements, STPs are typically provisioned in mated pairs.
TCAP
Transaction Capabilities Application Part, is a protocol for Signalling System 7 networks. Its primary purpose is to facilitate multiple concurrent dialogs between the same sub-systems on the same machines, using Transaction IDs to differentiate these, similar to the way TCP ports facilitate multiplexing connections between the same IP addresses on the Internet.
TCAP uses ASN.1 BER encoding, as well as the protocols it encapsulates, namely MAP in mobile phone networks or INAP in Intelligent Networks.
CAMEL Application Part ( CAP )
The CAMEL Application Part (CAP) is a signalling protocol used in the Intelligent Network (IN) architecture
是 智能网( IN ) 的信令协议， 与智能网通信都需要使用 CAP
SIGTRAN
是 SS7 的 user layer adaptation , 使用 IP 通信 ，用 SCTP 协议
也可以理解为 M3UA via SCTP protocol
SCTP
类似tcp的一种协议，提供SS7信令在IP上的可靠传送。对TCP进行了如下改进：可靠传递、灵活排序、多传输地址
SSN number
ss7 sub system number
PBX
A PBX (private branch exchange) is a telephone system within an enterprise that switches calls between enterprise users on local lines while allowing all users to share a certain number of external phone lines. The main purpose of a PBX is to save the cost of requiring a line for each user to the telephone company’s central office. (类似家用路由器)
Global Title vs. Point Code
A Global Title (GT) is an address used in the SCCP protocol for routing signaling messages on telecommunications networks. In theory, a global title is a unique address which refers to only one destination, though in practice destinations can change over time.
The Global Title is similar in purpose on the PSTN to the host name on the internet. In design, however, global titles are quite different. The structure is usually hierarchical, the value can be of variable length, and is not necessarily a wholly numeric value—though it often is for issues of backwards compatibility and association with regular telephone numbers.
An SS7 point code is similar to an IP address in an IP network. It is a unique address for a node (Signaling Point, or SP), used in MTP layer 3 to identify the destination of a message signal unit (MSU).
In such a message you will find an OPC (Originating Point Code) and a DPC (Destination Point Code); sometimes documents also refer to it as a signaling point code. Depending on the network, a point code can be 24 bits (North America, China), 16 bits (Japan), or 14 bits (ITU standard, International SS7 network and most countries) in length.
For example Global titles belong to your mobile network looks like your mobile number: +xx248283828 where xx is your contry code
Pont code looks like: 8578, 600 etc.
MTP2
MTP2 is the Data Link layer used with in SS7; it is used to carry MTP3 traffic from point to point.
是物理层
