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INTERNATIONAL TELECOMMUNICATION |
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TELECOMMUNICATION STUDY PERIOD 2001-2004 |
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Original:
English |
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Title: |
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Abstract
This
contribution provides
three protocol configurations to transmit the SS7 signalling based on SIGTRAN
[1, 2] between IP-CMEs to
give a basis for further discussion.
This contribution is intended to provide protocol configurations which should be discussed in chapter 8.6.1 Transmission over IP-based networks in G.769.
8.6.1 Transmission over IP-based networks in G.769.
Both of the channels (TDM time slots) in a SW, such as call signalling channel and bearer channels (Voice, Facsimile and VBD channels) are connected to IP-CME. In short, the call signalling messages are passed transparently between IP-CMEs over IP-based networks using following means. See Figure 3.
1) SIGTRAN transmission -IETF RFC 2719,
IETF RFC 2960;
2) Clear channel (64kbit/s) transmission.
1. Protocol configurations based on SIGTRAN
We provide following three protocol configurations based on the SIGTRAN implementation. Especially, SCTP is a reliable transport protocol operating on top IP such TCP. It offers acknowledged error-free non-duplicated transfer of signalling messages. Detection of data corruption, loss of data and duplication of data is achieved by using checksums and sequence numbers. A selective retransmission mechanism is applied to correct loss or corruption of data.
There are several alternatives for transmission schemes of SS7
signalling optimized for IP-CME. Followings are examples of the protocol
configurations.
1) Configuration
1
IWF
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MTP2
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SCTP
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MTP1
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IP
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IWF
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SCTP
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MTP2
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IP
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MTP1
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2) Configuration
2
M2UA
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MTP2
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SCTP
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IP
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MTP1
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MTP2
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M2UA
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SCTP
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MTP1
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IP
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3) Configuration 3
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MTP3 |
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MTP2 |
M2PA |
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MTP1 |
SCTP |
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IP |
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MTP3 |
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M2PA |
MTP2 |
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SCTP |
MTP1 |
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IP |
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Note:
IWF: Interworking Function.
M2UA: It provides the services of MTP2 in a client-server situation.
M2PA: It provides the services of MTP2 in a peer-to-peer situation.
2. Conclusion
This contribution provided
examples of the protocol configuration of the transmission scheme of SS7
signalling based on SIGTRAN which should be supported by IP-CME.
Reference
[1] IETF RFC 2719 (10/99), Framework
Architecture for Signalling Transport.
[2] IETF RFC 2960 (10/00), Stream Control Transmission Protocol.