Each ASP in this set may be active, inactive, or unavailable. Flow Control Local Management at an ASP may wish to stop traffic across an SCTP association to temporarily remove the association from service or to perform testing and maintenance activity. The function could optionally be used to control the start of traffic on to a newly available SCTP association.
Congestion Management The M3UA layer is informed of local and IP network congestion by means of an implementation-dependent function e.
The following rules apply see Section 3. Sample Configuration 1. It also provides network status information to one or both sides of the network. In addition, as an implementation and network option, restricted destinations are communicated from MTP network management to the local M3UA-resident management function.
For forward compatibility, all Message Types may have attached parameters even if none are specified in this version. Common Message Header The protocol messages for MTP3-User Adaptation require a message header that contains the adaptation layer version, the message type, and message length.
The supported versions are as follows: 1 Release 1. Variable-Length Parameter Format M3UA messages consist of a Common Header followed by zero or more variable-length parameters, as defined by the message type. All the parameters contained in a message are defined in a Tag Length-Value format, as shown below. Unless explicitly stated or shown in a message format diagram, only one parameter of the same type is allowed in a message. Parameter Tag: 16 bits unsigned integer The Tag field is a bit identifier of the type of parameter.
It takes a value of 0 to Common parameters used by adaptation layers are in the range of 0x00 to 0x3f. M3UA-specific parameters have Tags in the range 0x to 0x02ff. The parameter Tags defined are as follows: Common Parameters. Values other than those defined in specific parameter descriptions are reserved for use by the IETF. Parameter Length: 16 bits unsigned integer The Parameter Length field contains the size of the parameter in octets, including the Parameter Tag, Parameter Length, and Parameter Value fields.
Thus, a parameter with a zero-length Parameter Value field would have a Length field of 4. The Parameter Length does not include any padding octets. If the parameter contains subparameters, the Parameter Length field will include all the octets of each subparameter, including subparameter padding octets if there are any.
Parameter Value: variable length The Parameter Value field contains the actual information to be transferred in the parameter. If the length of the parameter is not a multiple of 4 octets, the sender pads the Parameter at the end i. The length of the padding is NOT included in the parameter length field. The receiver MUST ignore the padding octets. Transfer Messages The following section describes the Transfer messages and parameter contents.
In other cases, the parameter may be configured to be present for the use of the receiver. Where the optional Network Appearance parameter is present, it MUST be the first parameter in the message, as it defines the format of the Protocol Data field. Where multiple Routing Keys and Routing Contexts are used across a common association, the Routing Context MUST be sent to identify the traffic flow, assisting in the internal distribution of Data messages.
Service Indicator: 8 bits unsigned integer The Service Indicator field contains the SI field from the original SS7 message justified to the least significant bit.
The MP bits are aligned to the least significant bit. As an implementation option, the SG may suppress the sending of subsequent "response" DUNA messages regarding a certain unreachable SS7 destination for a certain period to give the remote side time to react. Affected Point Codes that are less than 24 bits are padded on the left to the bit boundary. Including multiple Affected PCs may be useful when receipt of an MTP3 management message or a linkset event simultaneously affects the availability status of a list of destinations at an SG.
Identifying a contiguous range of Affected DPCs may be useful when receipt of an MTP3 management message or a linkset event simultaneously affects the availability status of a series of destinations at an SG.
The Mask parameter is an integer representing a bit mask that can be applied to the related Affected PC field. The bit mask identifies how many bits of the Affected PC field are significant and which are effectively "wildcarded". For example, a mask of "8" indicates that the last eight bits of the PC are "wildcarded".
A mask of "3" indicates that the last three bits of the PC are "wildcarded". A mask value equal or greater than the number of bits in the PC indicates that the entire network appearance is affected; this is used to indicate network isolation to the ASP. It is recommended that during normal operation traffic handling the mask field of the Affected Point Code parameter in the DAUD message be kept to a zero value in order to avoid SG overloading.
For some MTP protocol variants e. This timer will be useful in cases where the peer node fails to indicate congestion abatement. The Affected Point Code parameter can be used to indicate congestion of multiple destinations or ranges of destinations. It contains the point code of the originator of the message that triggered the SCON message. A Concerned Point Code that is less than 24 bits is padded on the left to the bit boundary.
For MTP congestion methods without multiple congestion levels e. Congestion Level field: 8 bits unsigned integer The Congestion Level field, associated with all of the Affected DPC s in the Affected Destinations parameter, contains one of the following values: 0 No Congestion or Undefined 1 Congestion Level 1 2 Congestion Level 2 3 Congestion Level 3 The congestion levels are defined in the congestion method in the appropriate national MTP recommendations [ 7 , 8 ].
The valid values for the Unavailability Cause parameter are shown in the following table. The M3UA layer at the ASP is expected to send traffic to the affected destination via an alternate SG with a route of equal priority, but only if such an alternate route exists and is available. If the affected destination is currently considered unavailable by the ASP, The MTP3-User should be informed that traffic to the affected destination can be resumed.
This message is optional for the SG to send, and it is optional for the ASP to act on any information received in the message. It is for use in the "STP" case described in Section 1. The receiver of a BEAT message does not process this field, as it is only of significance to the sender.
It includes all the parameters of the received BEAT message, without any change. The sender of this message expects that the receiver of this message will create a Routing Key entry and assign a unique Routing Context value to it, if the Routing Key entry does not already exist.
The Routing Key parameter may be present multiple times in the same message. This is used to allow the registration of multiple Routing Keys in a single message. For an alias point code configuration, the DPC parameter would be repeated for each point code. Where Network Appearance is not specified and there is only one Network Appearance, then Network Appearance is implied. Where an SI parameter does not contain a multiple of four SIs, the parameter is padded out to byte alignment.
It is set to "0" if the registration was not successful. Deregistration Status: bit integer The Deregistration Result Status field indicates the success or the reason for failure of the deregistration. An Application Server Process may be configured to process traffic for more than one logical Application Server.
See Section 3. Error The Error message is used to notify a peer of an error event associated with an incoming message. For example, the message type might be unexpected given the current state, or a parameter value might be invalid.
The receiving end responds with an Error message, indicating the version the receiving node supports, and notifies layer management.
The "Unsupported Message Class" error is sent if a message with an unexpected or unsupported Message Class is received. For this error, the Diagnostic Information parameter MUST be included with the first 40 octets of the offending message. The "Unsupported Message Type" error is sent if a message with an unexpected or unsupported Message Type is received.
An example would be a case in which the SGP did not support loadsharing. The "Unexpected Message" error MAY be sent if a defined and recognized message is received that is not expected in the current state in some cases, the ASP may optionally silently discard the message and not send an Error message.
The "Protocol Error" error is sent for any protocol anomaly i. The "Invalid Parameter Value" error is sent if a message is received with an invalid parameter value e. The "Parameter Field Error" would be sent if a message is received with a parameter having a wrong length field.
The "Unexpected Parameter" error would be sent if a message contains an invalid parameter. This error is also sent if a conditional parameter is not included in the message but is required in the context of the received message.
The "Invalid Routing Context" error is sent if a message is received from a peer with an invalid unconfigured Routing Context value. The "No Configured AS for ASP" error is sent if a message is received from a peer without a Routing Context parameter and it is not known by configuration data which Application Servers are referenced.
Diagnostic Information: variable length When included, the optional Diagnostic Information can be any information germane to the error condition, to assist in identification of the error condition. A Diagnostic Information parameter with a zero length parameter is not considered an error this means that the Length field in the TLV will be set to 4. The value reflects the new state of the Application Server. Procedures The M3UA layer needs to respond to various local primitives it receives from other layers, as well as to the messages that it receives from the peer M3UA layer.
This section describes the M3UA procedures in response to these events. The M3UA message distribution function see Section 1. In addition, the message needs to be sent on the appropriate SCTP stream, again taking care to meet the message sequencing needs of the signalling application.
Receipt of Primitives from the Layer Management On receiving primitives from the local Layer Management, the M3UA layer will take the requested action and provide an appropriate response primitive to Layer Management. No peer protocol is invoked. These indications can also be generated based on local M3UA events. No M3UA peer protocol is invoked. Upon successful completion, a corresponding confirm primitive is provided by the M3UA layer to Layer Management. If an invocation is unsuccessful, an Error indication primitive is provided in the primitive.
Two IPSP models are defined as follows: 1. This means that a set of requests from one end and acknowledgements from the other will be enough. SCTP provides for unique needs of the telephony network.
SCTP Protocol that met the needs of determinism, reliability and timeliness. UDP: Best effort delivery, but not reliable. TCP: Guaranteed delivery, but not timely. SCTP: Deterministic, reliable and timely. SCTP Deals with framed messages. Multi-homing support, end-points can be more than one IP address. Delivers data in chunks in independent streams, eliminates head-of-the line blocking.
Path selection of a primary path and monitoring of connectivity. This allows the same services to be offered but adds flexibility and efficiency.
M3UA Protocol M3UA message format includes a common header followed by zero or more parameters as determined by the type of message. M3UA Protocol. M3UA Protocol Each message class and type has zero or more parameters, far too many to list here. It appears to be a signaling point to the SS7 network. A Signaling Gateway process is a process instance of the SG.
It interacts with the ASP. How is M3UA commonly deployed? How can M3UA be configured? As an application server process on an application server. Point to point or as a gateway. Open navigation menu. Close suggestions Search Search. User Settings. But it is a little different from other adaptation layers. It is for peer adaptation, while other Sigtran layers e. What peer mean? For m2pa both the peer have the same functionality, While in user adaptation, one peer is an SG.
After having an introduction about M2PA, now we will discuss some differences between m2pa and m3ua. Save my name, email, and website in this browser for the next time I comment.
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