SS7

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Diagram of the SS7 stack

SS7 is a signaling protocol which is used to set up and tear down phone calls. It also provides support for such functionality as local number portability, Short Messaging Service (SMS), prepaid billing and number translation.

The configuration of SS7 requires that the physical layer, through to the transport layer, and up to the application layer be configured. SS7 configuration involves configuring values for MTP2 Layer, MTP3 Layer, SCCP, and ISUP.

A conceptual illustration of the SS7 protocol stack is shown on the right. In the SS7 architecture, every layer has very specific task and responsibilities to provide to upper layers. Looking at the figure on the right, we see that an SS7 stack covers all levels of the OSI model from physical to application layer. Within this model, it is possible to replace one of more layers by another protocol as long as it provides the same functionalities. In a base call control application over a TDM network, the SS7 stack required would include layers MTP1 Layer, MTP2, MTP3 and ISUP or TUP.

It is worth pointing out that, by being layered in different functional groups, SS7 was built so that different nodes in the network don’t need to implement every portion of the protocol stack if they don’t require to.


Contents

TelcoBridges and SS7

TelcoBridges provides SS7 support with all of its media gateway, VAS development platform and monitoring devices. SS7 functionality is licensed separately and can be provided at initial purchase or added later on via a software license upgrade.

SS7 signaling is configured once for the entire Tmedia or Tdev system. Any one Tdev unit is capable of running the entire SS7 signaling stack for all the Tdev units in a system.

Systems developed using TelcoBridges hardware can support up to a maximum of 64 point codes. It is worth noting that a single point code can be used for 2 or more devices configured as a single system.

High availability (HA) has been designed into the architecture of the Tmedia product such that the failure of an SS7 stack on one Tmedia unit will be taken over by the SS7 stack of another Tmedia unit.


Click for further information on:

Maximum Capacity

Release MTP2
HSL
MTP2
LSL
MTP3
Links
MTP3
Linksets
OPC DPC
Routes
ISUP
Networks
ISUP
Userparts
SCCP
Userparts
TCAP
Userparts
CIC Groups
ISUP stack
CICs
ISUP stack
MTP2 Link
redundancy
MTP3
Redundancy
ISUP
Redundancy
TMG800 2.2-2.7 2 64 64 64 64 128 8 8 8 8 300 512 Yes N/A N/A
2.8 2 64 64 256 64 256 8 8 8 8 300 512 Yes N/A N/A
2.9+ 2 64 64 256 64 512 8 8 8 8 300 512 Yes N/A N/A
TMG3200 2.2-2.7 2 64 64 64 64 128 8 8 8 8 300 2048 Yes N/A N/A
2.8 2 64 64 256 64 256 8 8 8 8 300 2048 Yes N/A N/A
2.9+ 2 64 64 256 64 512 8 8 8 8 300 2048 Yes N/A N/A
TMG7800 2.2-2.7 32
(2/Tmedia)
256
(64/Tmedia)
256
(64/Tmedia)
16 64 128 8 8 8 8 300 30000 Yes Yes Yes
2.8 32
(2/Tmedia)
512
(64/Tmedia)
512
(64/Tmedia)
16 64 256 16 8 8 8 300 30000 Yes Yes Yes
2.9+ 32
(2/Tmedia)
512
(64/Tmedia)
512
(64/Tmedia)
16 64 512 16 8 8 8 300 30000 Yes Yes Yes

Supported SS7 Link types

Typically:

  • A Link
  • F Link

The following types are also supported in some circumstances:

  • B/D Link
  • C Link
  • E Link

Configuration

Configuration

References

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