MTP2:Architecture
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− | + | [[MTP2 Layer|MTP Level 2]] defines the functions and procedures of the signaling system for providing reliable transfer of signaling messages over a signaling link. The MTP2 layer is a service provider to the MTP3 Link layer. The MTP2 layer is a service user of [[Web_Portal_Tutorial_Guide#Line_Interfaces|line interfaces / line services”]] as seen in the shown in the figure below. | |
− | ''' | + | [[Image:MTP2-architecture.jpg|800px|MTP2 architecture schematic]] |
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+ | MTP2 can be used in conjunction with an above local MTP3 layer and can be used as a standalone and communicates with remote MTP3 layer (host application). See the connection mode table in the MTP2 Configuration section. | ||
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+ | [[Image:filename|thumb|widthpx| ]] | ||
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+ | A MTP2 Link must be associated with one Trunk instance. It’s a 1-to-1 association. MTP Level 2 defines the functions and procedures of the signaling system for providing reliable transfer of signaling messages over a signaling link. | ||
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+ | '''IMPORTANT NOTE:''' It is important to ensure that the received and transmitted clocks of the Trunk were synchronized. This can be useful for removing/limiting undesirable FIB and BSN errors. See section “Clock Configurations” in the TB640 user’s guide. | ||
Revision as of 08:58, 25 August 2009
MTP Level 2 defines the functions and procedures of the signaling system for providing reliable transfer of signaling messages over a signaling link. The MTP2 layer is a service provider to the MTP3 Link layer. The MTP2 layer is a service user of line interfaces / line services” as seen in the shown in the figure below.
MTP2 can be used in conjunction with an above local MTP3 layer and can be used as a standalone and communicates with remote MTP3 layer (host application). See the connection mode table in the MTP2 Configuration section.
A MTP2 Link must be associated with one Trunk instance. It’s a 1-to-1 association. MTP Level 2 defines the functions and procedures of the signaling system for providing reliable transfer of signaling messages over a signaling link.
IMPORTANT NOTE: It is important to ensure that the received and transmitted clocks of the Trunk were synchronized. This can be useful for removing/limiting undesirable FIB and BSN errors. See section “Clock Configurations” in the TB640 user’s guide.
Priorities
No pre-emption of data occurs in the process of being transmitted or requiring retransmission. Only a single congestion priority is supported for ANSI and ITU. For a TTC/NTT link, transmitted data buffers are prioritized based on the priority indicated by MTP Level 3.
Flow control
The MTP Level 2 software regulates data flow when resource utilization (such as buffer pool size or queue length) reaches specifies thresholds. For each threshold, MTP Level 2 performs one of the following actions:
- Informs the layer manager about flow control.
- Sends a link status signal unit with status "B" (busy).
- Sends a flow control indication to the upper layer.
The MTP Level 2 software prevents deadlocks and overload conditions from occurring.