Message Discrimination

Because A-Port provides translation of ported numbers, it provides a method to identify which messages should receive A-Port and which should receive GTT processing. This task of identification is provided via a service selector table (SRVSEL) in which the user can define A-Port service for messages matching a combination of selectors. If a selector match is not found, then the message falls through to GTT- or MTP- routing (in case of MTP routing).

RN Prefix Deletion - SCCP

The decoded SCCP CdPA digits can have a Routing Number (RN) concatenated with the Mobile Directory dNumber (MDN) number in two forms:

• RN + DN

• CC+RN+DN (where CC is the Country Code)

When the Service Nature of Address Indicator (SNAI) is one of the following, A-Port compares the decoded MDN number with the list of provisioned home RN prefixes defined in the Real Time Database (RTDB).

• RNIDN ( Routing Number, International Directory Number)
• RNNDN (Routing Number, National Directory Number)
• RNSDN ( Routing Number, Subscriber Directory Number)
• CCRNDN (Country Code, Routing Number, National Directory Number)

If a match is found, A-Port strips off the RN digits from the number. Number conditioning, if required, is performed after deleting the RN.

When the SNAI is CCRNDN (Country Code, Routing Number, National Directory Number), A-Port first compares the CC to the DEFCC (Default Country Code) list:

• If CC is not equal to the DEFCC, the message falls through to GTT.

• If CC=DEFCC, then A-Port compares the digits after CC with the list of provisioned Home RN prefixes that are defined in the RTDB. If a match is found, then A-Port strips off the RN digits from the number. If no match is found, the no-prefix deletion is performed and A-Port processing continues.

RN Prefix Deletion - TCAP

The decoded MAP MDN digits can have a RN concatenated with the MDN number in two forms:

• RN + DN

• CC+RN+DN

Number conditioning, if required, is performed after deleting the RN.

Number Conditioning

The RTDB stores international MDNs only. The received MDN number or SCCP CdPA digits may need to be converted to an international number to perform a database lookup.

A-Port performs number conditioning upon successful decode and verification of the message. Home RN and IEC (International Escape Code) or NEC (National Escape Code) prefixes are removed. The MDN is conditioned to international number format based on the service Nature of Address Indicator: SNAI for SCCP, TCAP SNAI for TCAP, or MTP Location Request Message (LOCREQ) NAI for MTP.

Database Lookup

A-Port performs database lookup using the conditioned DN digits encoded in Called Party. The database lookup yields one of four possible outcomes:

• Match is Found with Network Entity (NE) Assigned

  For subscriber entries with an RN and any Portability Type (PT), LOCREQ is returned with an RN and any IS41 messages are relayed. GTT is applied to any GSM or non-TCAP messages.

  For subscriber entries with a Signalling Point (SP) and any Portability Type (PT), LOCREQ and any IS41 messages are relayed. GTT is applied to any GSM or non-TCAP messages.

• Match is Found Without NE

  A data entry in the database is found if a subscriber entry in the database, either an individual DN entry or a DN block, matches the conditioned Called Party.

  If an entry is found without an NE assigned and PT= 0, 1, 2, 36, or no PT, the LOCREQ is returned without an NE. GTT is applied to any IS41 message

  If an entry is found without an NE assigned and PT= 5 or 6, the LOCREQ is routed via GTT.

  GTT is applied to any IS41 message if an entry is found without an NE assigned. The EAGLE modifies only the MTP and SCCP information as required by standard GTT and keeps the TCAP portion of the message intact.

• Number conditioning fails. The DN is not found in the RTDB, or the DN is found with non-A-Port data.

  Either the number has never been ported or is an unknown number. The EAGLE routes the message by normal GTT/MTP routing. The EAGLE modifies only the MTP and SCCP information as required by normal GTT/MTP routing, if required, as follows:

  • Perform GTT if the incoming message is sent to the EAGLE Self Point Code.
  • Route the message to the MTP Destination Point Code (DPC) if the incoming message is MTP-routed. (The MTP DPC of the message is not the EAGLE Self Point Code.)

  The TCAP portion of the message remains intact.

  Normal routing is performing GTT if the incoming message is sent to the EAGLE Self Point Code. Normal routing is routing the message to the MTPDPC if the incoming message is MTP-routed. (The MTPDPC of the message is not the EAGLE Self Point Code.)

• A-Port modifies the TCAP information for LOCREQ messages only when a HomeRN was deleted from the TCAP DN and LOCREQ RMHRN = YES. Any gaps in the data caused by a change in field length will be resolved by shifting the remaining information up. Any IEC or NEC code is left.

  Because a DN may be the target of A-Port, G-Port, or Migration message processing in a hybrid network where an operator owns both GSM and IS41 network, message processing call disposition is based on which applications are turned on. Table 2-1 summarizes A-Port message processing.

Database lookup results in the following:

1. Applying GTT or

2. Relaying the message to the destination as noted in the database or

3. Returning an acknowledge message to the originating switch.

Message Relay describes how the EAGLE formulates a relayed message or a returned ACK.

Message Relay

• If DigitAction = none, the EAGLE does not overwrite the SCCP CdPA GTA.
• For all other values, the EAGLE formats the SCCP CdPA GTA according to the value assigned to DigitAction.

Returning Acknowledgement

When a LOCREQ response/ACK is returned, the EAGLE follows the LOCREQ encoding rules along with the following enhancements for added flexibility:

• Allow users to specify which TCAP LOCREQ parameter (the TCAP Outgoing Called Party parameter) encodes the RN (and/or DN) information

• Allow users to specify the Digit Type value to encode the TCAP Outgoing Called Party parameter

• Allow users to specify the value to encode the Nature of Number field of the TCAP Outgoing Called Party parameter

• Allow users to specify the value to encode the Numbering Plan field of the TCAP Outgoing Called Party parameter

• Allow users to specify the digit encoding format of the LOCREQ TCAP Outgoing Called Party parameter;

• Allow users to specify the MSCID values to be encoded in the LOCREQ message

• Allow users to specify the Electronic Serial Number ( ESN) values to be encoded in the LOCREQ message

• Allow users to specify how the digits of the LOCREQ MIN parameter shall be encoded

LOCREQ Query Response Processing

For LOCREQ Query Response processing to occur, the LOCREQ Query Response feature must be enabled and turned on and the IS41OPTS option LOCREQRSPND must be set to on. The LOCREQ Query Response feature processes only ANSI TCAP Query with Permission messages with an Operation Code of LocReq.

LOCREQ Query Response processing functions include:

• The DN is retrieved from the TCAP portion.

• The NAI is determined based on the MTPLOCREQNAI value provisioned in the IS41OPTS table.

• A-Port or IGM number conditioning (for example, HomeRN Deletion and IEC/NEC Deletion) is applied to the DN.

• MNP Circular Route Prevention is not applied to LOCREQ query messages processed by the LOCREQ Query Response feature.

• Every LOCREQ query message processed by the LOCREQ Query Response feature is acknowledged with a response message.

Figure 2-1 shows the logic to determine the RN digits used in the LOCREQ query response.

Figure 2-1 LOCREQ Query Reponse RN Determination

LOCREQ Query Response Errors

The LOCREQ Query Response feature responds to LOCREQ queries unless one of these errors occurs.

Decode Errors

Error result - (X)UDTS:Unqualified is generated; UIM is issued; MSU is discarded.

• The TCAP message is incorrectly formatted (invalid parameter tag or length).

• Called Party Number or Dialed Digits parameter does not exist.

• Digits parameter is less than 4 bytes.

• Number of digits is greater than 21.

• Encoding scheme is not BCD.

• Numbering Plan is not Telephony or ISDN.

Number Conditioning Errors

Error result - (X)UDTS:Unqualified is generated; UIM is issued; MSU is discarded.

• Default country code (DEFCC) parameter is required, but is not provisioned.

• Default Network Destination Code (DEFNDC) parameter is required, but is not provisioned.

• International (conditioned) digits are less than 5 or greater than 15.

Encode Errors

Error result - No response message is generated; UIM is issued; MSU is discarded.

• CgPA PC/OPC is not in the route table. CgPA PC is used if present in message,;otherwise OPC is used.

• CgPA PC/OPC is an Alias. No conversion is allowed.

LOCREQ Query Response Maintenance and Measurements

The LOCREQ Query Response feature increments counters against MNP service in the rept-stat-sccp output.

• Failure counter is incremented if a Return Result cannot be generated because of decode errors, number conditioning errors or encode errors.

• Failure counter is incremented if a message is received and MNP service state is offline.

• Warning counter is incremented if GRN was required but was missing, and the Return Result was sent.

• Success counter is incremented if a Return Result is generated, except if the Warning counter was incremented for missing GRN.

LOCREQ Query Response feature increments these Measurement registers, also used by A-Port and IGM features, if a LOCREQ query response message generates successfully:

• IS41LRMRCV

• IS41LRRTRN

• APLRACK (per SSP)

LOCREQ Query Response feature increments these Measurement registers, also used by A-Port and IGM features, if a LOCREQ query response message fails to be generated:

• IS41LRMRCV

• IS41LRERR

The MTP Msgs for SCCP Apps and MTP Routed GWS Stop Action features forward MTP routed SCCP messages to the Service Module cards. The SCCP messages forwarded by either feature are processed in the same way on the Service Module cards. The difference between the two features is that the MTP Routed GWS Stop Action feature filters messages based on provisioned Gateway Screening rules on a per linkset basis and forwards only UDT, UDTS, XUDT and XUDTS SCCP messages to Service Module cards, while the MTP Msgs for SCCP Apps feature forwards all MTP routed SCCP messages to the Service Module card without filtering. Because the MTP Routed GWS Stop Action feature selectively forwards the messages to the Service Module card, the feature has less impact on SCCP performance than the MTP Msgs for SCCP Apps feature. The features can coexist, which means that both features can be turned on in the same system.

MTP Msgs for SCCP Apps

MTP routed SCCP messages are supported with the MTP Msgs for SCCP Apps feature. LOCREQ and SMSREQ messages are supported. A Feature Access Key (FAK) for part number 893-0174-01 is required to enable the MTP Msgs for SCCP Apps feature. ThisThe MTP Msgs for SCCP Apps feature (part number 893-0174-01) can be turned on and off, but cannot be enabled with a temporary FAK. GTT must be on to enable the MTP Msgs for SCCP Apps feature.

After the MTP Msgs for SCCP Apps feature is turned on, all SCCP messages are routed to Service Module cards. The Service Module card then performs SCCP decode/verification. Use of the MTP Msgs for SCCP Apps feature adversely affects the SCCP capacity because all of these messages are counted under SCCP capacity.

If the MTP routed messages have CdPA RI=GT or SSN and GTI ≠ 0 (GTI = 2 or 4), then a service selection (SRVSEL) lookup is performed using the SCCP CdPA information. If the result of the lookup is MNP service, then the message is sent to MNP handling. If a service selector does not match or the service is OFFLINE, then MTP routing is performed on the messages. MNP SCCP Service re-route is not performed on MTP routed messages.

If the MTP routed messages have CdPA GTI=0, the TCAP portion of ANSI TCAP messages is decoded. SMSMR service is invoked for SMDPP messages; IAR Base feature is invoked for Analyzed messages. For all other messages, MNP service is invoked.

MNP handling checks whether the TCAP portion of the message is ITU or ANSI.

If the message has ANSI TCAP, then:

• General TCAP/MAP verification for A-Port is performed if the A-Port or IGM feature is turned on. Only LOCREQ and SMSREQ messages are handled by A-Port or IGM for MTP routed messages.

• When GTI ≠ 0, message relay is performed on non-LOCREQ and non-SMSREQ ANSI TCAP messages based on the SCCP CdPA portion of the message.

• When GTI = 0, MTP routing is performed on non-LOCREQ ANSI TCAP messages.

If the message has ITU TCAP, the IGM feature is on, and GTI ≠ 0, then:

• The message is considered for relaying based on the RTDB lookup results. General TCAP/MAP verification is not performed on the message.

• Message relay is performed based on the SCCP CdPA portion of the message with GTI = 2 or 4.

If the message has ITU TCAP, the IGM feature is on, and GTI = 0, then MTP routing of the message is performed.

ITUN-ANSI SMS Conversion is not affected by the MTP Msgs for SCCP Apps feature; ITUN-ANSI SMS Conversion handles only Registration Notification and SMS Notification messages.

MTP Routed GWS Stop Action

The MTP Routed GWS Stop Action feature (part number 893-0356-01) provides a Gateway Screening (GWS) stop action: sccp. This stop action allows IS41-based features to process MTP routed traffic. GWS rules are used to filter MTP routed SCCP messages (UDT, UDTS, XUDT, and XUDTS) on a per linkset basis. The messages are then forwarded to Service Module cards for processing by features that support MTP routed messages based on Service Selection criteria. A Feature Access Key (FAK) for part number 893-0356-01 is required to enable the MTP Routed GWS Stop Action feature. This feature can be turned on and off, but cannot be enabled with a temporary FAK. GTT must be on to enable the MTP Routed GWS Stop Action feature. The MTP Routed GWS Stop Action feature must be enabled before the sccp stop action can be provisioned, and before message processing can occur. The sccp stop action must be the last stop action in the GWS action set.

If the MTP Msgs for SCCP Apps feature is turned on, all SCCP messages are forwarded to Service Module cards without the sccp GWS stop action being executed, regardless of whether the MTP Routed GWS Stop Action feature is turned on.

After provisioning, the sccp stop action can be used by these features:

• A-Port

• G-Flex

• Info Analyzed Relay ASD

• Info Analyzed Relay Base

• Info Analyzed Relay GRN

• Info Analyzed Relay NP

• IS41 GSM Migration (IGM)

• ITUN-ANSI SMS Conversion

• MNP Circular Route Prevention

• MO-Based IS41SMS NP

• MO SMS ASD

• MO SMS B-Party Routing

• MO SMS GRN

• MO SMS IS41 to GSM Migration

• MTP MAP Screening

• MT-Based IS41 SMS NP

Refer to Database Administration – GWS User's Guide for additional information and provisioning procedures for the MTP Routed GWS Stop Action feature.

SMSREQ Handling for Migrated or Ported Subscribers

The SMSREQ Handling for Migrated or Ported Subscribers enhancement allows MTP routed SMSREQ messages to be supported by A-Port, IGM, MNPCRP, and MT-Based IS41 SMS NP features. Service selection criteria for MTP routed SMSREQ messages is the same for MTP routed LOCREQ messages. The MNP service processing for MTP routed SMSREQ messages is the same for Global Title (GT) routed SMSREQ messages. However, MTP routing is performed on MTP routed messages when these messages fall through from the MNP service. Feature precedence is applied for SMSREQ messages as shown:

1. MNPCRP - If a circular route condition is detected, a UIM is generated and MTP routing is performed on the message.

2. IGM - If the DN is own-network GSM subscriber (Portability Type = 5) and SMSREQBYPASS = No, then send an SMSREQ Error Response (Return Result message) to the originator with SMS Access Denied Reason = 5.

3. MT-Based IS41 SMS NP - If the DN matches the MT-Based IS41 SMS NP feature criteria (IS41SMSOPTS:MTSMSTYPE), the SMSREQ response is generated.

4. A-Port - A-Port relays the message based on the RTDB lookup result. If relay information is not present in the RTDB data associated with the DN, then the message is MTP routed.

5. If A-Port is not turned on, then IGM relays the SMSREQ message for only own-network subscribers if the SMSREQ response is not previously sent for subscribers not handled by IGM. If relay information is not present in the Network Entity Type (RN/SP) associated with the DN or if Network Entity Type indicates an Other Licensed Operator (OLO) subscriber, then the message is MTP routed.

6. If none of the feature processing in the previous items is performed, then the message is MTP routed.

If a feature in the precedence list is off, processing by that feature is not performed.

Service State Management

Service state management is part of the MNP SCCP Service Re-Route Capability. Service state is used to indicate the current state of MNP, either ONLINE or OFFLINE. Service state also gives the user the option to mark MNP as OFFLINE or ONLINE based on the current behavior. If a MNP problem is identified, MNP can be marked OFFLINE to initiate the re-routing procedure. When Service Module cards need to be reloaded, MNP can be marked OFFLINE until enough cards are in-service and then bring MNP ONLINE in a controlled fashion.

When the MNP feature is turned on and the MNP service state is set to OFFLINE, the user can change the service to ONLINE at any point. Once the feature is turned ONLINE, MNP will start processing messages if at least one Service Module card is IS-NR (In Service - Normal).

The MNP service can be set to OFFLINE at any point. This causes the EAGLE to stop processing MNP traffic and re-routing is performed.

The MNP service state is persistent. Booting the OAM or all Service Module cards will not change the service state. Commands must be used to change the service state.

MNP Re-Routing

Re-Routing is applied to all MNP messages (based on SRVSEL). There is no distinction of Destination Point Code (DPC) of the messages. The DPC of the message can be either True, Secondary, or Capability Point code.

MNP Capability Point Codes

Capability Point Codes (CPC) are supported for MNP. The use of MNP capability point code allows the adjacent nodes to know about MNP outages. When MNP is taken offline though administrative commands, all traffic destined to that MNP node will result in a Transfer Prohibited (TFP) message being sent to the adjacent node about the MNP CPC. The TFP response to the adjacent node causes the traffic originating nodes to stop sending MNP traffic to this node. All MNP traffic coming into this node is sent to the alternate MNP nodes. Adjacent nodes will initiate route-set-test procedures after receipt of the TFP response.

If the messages are destined to the EAGLE true point code, then TFP messages are not generated when the MNP service is OFFLINE. The originator would not be aware of the outage.

Once MNP is back in service on the EAGLE, a Transfer Allowed (TFA) message is sent to the traffic adjacent nodes in response to route-set-test message. The traffic originating nodes will then start sending MNP traffic to the original MNP node.

MNP Capability point codes can be provisioned when the MNP feature is ON. There can be more than one Capability Point Code assigned to MNP CPC Type.

MNP supports up to seven alternate PCs per domain. All six domains (ANSI, ITU-I, ITU-I Spare, ITU-N, ITU-N Spare, and ITU-N24) are supported. An entire set of alternate PCs is considered as a re-route set. A GTT option is supported for MNP re-route. When the MNP service is OFFLINE, MNP messages fall though to GTT based on the GTT option. This option is set to YES by default.

MNP SCCP Service Re-Route Capability Summary

If the MNP service is not normal (because the RTDB is not in sync with MPS or if cards are misrouting MNP messages) then the MNP service state should be changed to OFFLINE.

Before changing MNP service to OFFLINE, it should be decided what kind of re-routing will be used during the outage. The EAGLE supports re-routing data to alternate point codes or falling through to GTT as two possible options. Rerouting to alternate point code has priority over falling though to GTT. Examples of these two options follow:

Option 1

Define alternate point codes to re-route MNP traffic. This is the recommended option. Up to 7 alternate MNP nodes can be provisioned to re-route all the incoming MNP traffic. Once provisioned, the MNP service can be changed to OFFLINE. This example has any incoming being MNP traffic being load-shared to point codes based on the relative cost.

chg-sccp-serv:serv=mnp:pci1=1-1-1:rc1=10:pci2=2-2-2:rc2=10:pci3=3-3-3:rc3=10:pci4=4-4-4:rc4=10
chg-sccp-serv:serv=mnp:pci1=1-1-1:rc1=10:pci2=2-2-2:rc2=10:pci3=3-3-3:rc3=10:pci4=4-4-4:rc4=10
chg-sccp-serv:serv=mnp:pci1=1-1-1:rc1=10:pci2=2-2-2:rc2=10:pci3=3-3-3:rc3=10:pci4=4-4-4:rc4=10
chg-sccp-serv:serv=mnp:pci1=5-5-5:rc1=10:pci2=6-6-6:rc2=10:pci3=7-7-7:rc3=10:pci4=8-8-8:rc4=10 chg-sccp-serv:serv=mnp:state=offline

Option 2

With this option, default GTT translations are provisioned for MNP service. Then the chg-sccp-serv command is used to provision GTT=YES. All MNP messages will fall through to GTT. An example command follows:

chg-sccp-serv:serv=mnp:gtt=yes 

Once the MNP re-routing data is provisioned, MNP service can be changed to OFFLINE. At this point all MNP traffic will be re-routed. The user can take necessary steps to correct the MNP service on the node. Until all the cards or enough cards are in active state with valid MNP database, MNP service should not be changed to ONLINE.

The MT-Based IS41 SMS NP feature provides the following configurable options for controlling processing of SMS routing request messages and the content of the response:

• Selecting the Short Message Service Center (SMSC) response message type and digit format
• Specifying when an NP database lookup is considered to be successful
• Specifying the format of digits encoded in the response message.

The MT-Based IS41 SMS NP feature (part number 893-0199-01) has the following control requirements:

• The defcc parameter in the chg-stpopts command must be set to a value other than none before the feature can be turned on.
• A FAK for part number 893-0199-01
• The A-Port feature must be enabled before the MT-Based IS41 SMS NP feature can be enabled.
• The A-Port feature must be turned on before the MT-Based IS41 SMS NP feature can be turned on.
• The feature cannot be enabled if the LNP feature is enabled.
• A temporary FAK cannot be used to enable the feature.
• The feature cannot be turned off after it has been turned on.

The system level options that control the MT-Based IS41 SMS NP feature are stored in the IS41SMSOPTS database table. The MT-Based IS41 SMS NP feature must be enabled before the IS41SMSOPTS table can be provisioned.

The content of the IS41SMSOPTS table is used to help perform number conditioning, response generation, and other feature-specific options. Table 2-6 shows the options stored in the IS41SMSOPTS table, their possible values, and the action taken for each value.

This section illustrates the sequence of messages that occur in the processing of SMS messages destined for mobile-terminated subscribers in a number portability environment. Two scenarios exist:

• The called subscriber who is in the same network as the calling subscriber
• The called subscriber who is in a different network from the calling subscriber

MT-Based IS41 SMS NP Call Flow for In-Network Subscriber

Figure 2-2 MT-Based IS41 SMS NP Call Flow for In-Network Subscriber

MT-Based IS41 SMS NP Call Flow for Other-Network Subscriber

Figure 2-3 MT-Based IS41 SMS NP Call Flow for Other-Network Subscriber