TK155 ITU .pdf

TK155

EAGLE® STP Global Title Transaction ITU

Date issue Date issued d Nove Novembe mberr 200 2007 7 Documentt reference Documen reference & release version version TK155 TK1 55 – v5. v5.0 0

These presentation materials describe Tekelec's Tekelec's present plans to develop and make available to its customers certain products, features and functionality. Tekelec is only obligated to provide those deliverables specifically included in a written agreement signed by Tekelec and customer.

Notes

1

Agenda 



This class is intended intended to provide you with a full explanation explanation of Global Title Title Translation in the Eagle STP Course Outline Agenda includes the following sections: • • • •

MTP3 & SCCP Routing GTT definition GTT example GTT configuration

Tekelec Confidential

‘07 | 2

Notes

2

Agenda 



This class is intended intended to provide you with a full explanation explanation of Global Title Title Translation in the Eagle STP Course Outline Agenda includes the following sections: • • • •

MTP3 & SCCP Routing GTT definition GTT example GTT configuration


‘07 | 2

Notes

2

MTP3 & SCCP Routing


‘07 | 3

Notes

3

Routing 

There are 2 levels of routing in SS7 nodes, which are used depending on the type of message (MSU) : • MTP3 routing : Used mainly by ISUP messages • SCCP routing : Used mainly by MAP and INAP messages



SCCP routing also uses MTP3 routing. Together they provide a complete routing solution for SS7 exchanges


‘07 | 4

Notes • SS7 stands for Signaling System 7 • MSU stands for Message Signal Unit • MTP3 stands for Message Transfert Part level 3 • SCCP stands for Signaling Connection and Control Part

4

MTP3 Routing 



An ISUP MSU uses MTP3 routing OPC and DPC are sufficient information to enable the call to be routed to the next node, and to set up and manage an ISUP call

1000

DPC: 4000 OPC: 1000

DPC: 4000 OPC: 1000

SSP

SSP STP 2000


4000

‘07 | 5

Notes • ISUP stands for ISdn User Part • OPC stands for Originating Point Code • DPC stands for Destination Point Code • SSP stands for Service Switching Point • STP stands for Signaling Tranfert Point

5

SSN and MTP3 Routing 





An SSN (Sub System Number) is a specific application available on a node If this node is an SCP, an SSN is used to retrieve some information from the database associated with this application MTP3 routing is not able to route to an SSN or a database

1000

SSN 253

DPC: 3000 OPC: 1000

DPC: 3000 OPC: 1000

SSP STP 2000

SCP

SSN 251

3000 SSN 5


‘07 | 6

Notes • SSN stands for SubSystem Number • SCP stands for Service Control Point

6

SCCP Routing 



SCCP routing is used each time an application on a node needs to access a database Examples of SCCP routing: • Toll-free numbers: To request the database controlling Toll-free numbers to find the true number associated them, and thus to enable the call to be setup • Check the credit of prepaid numbers: To request that the database of prepaid numbers, checks on available credit before the call is setup • For MAP operations such as Location Update or Forward Short Message: To request the HLR to retrieve some information about a subscriber


‘07 | 7

Notes

7

Example of SCCP routing: Toll-free number 



The called number is used for the SCCP routing (GTA) SCCP routing also uses the SSN value to reach the database to request

1000

DPC: 2000 OPC: 1000 GTA: 0800345

DPC: 3000 OPC: 2000 SSN : 253

SSP STP 2000

SSN 253

SCP

SSN 251

3000 SSN 5

Caller dials: 08003456789


‘07 | 8

Notes • GTA stands for Global Title Address

8

Global Title Translation


‘07 | 9

Notes

9

Global Title Translation (GTT) 





SCCP uses a process called Global Title Translation to convert a GTA to a Point Code (and an SSN if possible, and if required) it uses this information to instruct MTP3 on where to route messages Basically, GTT analyses the CDPA from the SCCP field of the MSU and compares it with its GTT tables to find a Point Code (and an SSN if possible, and if required) of the next node There are 2 types of GTT: • Intermediate GTT : The point code and the SSN of the final node are not known • Final GTT : The point code and the SSN of the final node are known


‘07 | 10

Notes • CDPA stands for CalleD Party Address

10

Example of the 2 types of GTT Intermediate GTT

DPC: 1500 OPC: 1000 GTA: 0800345

SSN 253

DPC: 3000 OPC: 2000 SSN : 253

DPC: 2000 OPC: 1500 GTA: 0800345

SSN 251

1000

SSP STP 1500

STP 2000


SCP

SSN 5

3000

Final GTT Tekelec Confidential

‘07 | 11

Notes

11

MTP3 & SCCP fields of the MSU


‘07 | 12

Notes

12

Fields read for GTT in the MSU

TRANSMISSION DIRECTION

INAP or MAP Fields

TCAP Fields

SCCP Fields CDPA

Used to extract SCCP parameters as GTA Used to show if the MSU is for this STP or not

MTP3 Fields DPC

MTP2 Fields SI

Used to indicate the type of MSU


‘07 | 13

Notes • SI stands for Service Indicator: • SI=3 means the MSU is an SCCP MSU • SI=5 means the MSU is an ISUP MSU • If the DPC is not the Point Code of the Eagle STP, the MSU is just MTP3 routed • If the SI=3 and the DPC is the Point Code of the Eagle STP, the CDPA is parsed to extract the required information to perform GTT

13

Structure of the CDPA 

First Octet of the CDPA gives some information regarding the content of the following octets: This is the Address Indicator 8

7

NI

RI

6

5

4

3

GTI

2

1

SSN

PC

Used to show if a Point Code is present in the CDPA

Not used in ITU Used to indicate if the MSU needs further GTT or not

Used to show which field of the CDPA extract to perform GTT

Used to show if a SSN is present in the CDPA


‘07 | 14

Notes

• Bit 1: Indicate if the PC is present or not in the CDPA •0 - point code is not included •1 - point code is included • Bit 2: Indicate if the SSN is present or not in the CDPA •0 - subsystem number is not included •1 - subsystem number is included • Bits 3 thru 6 are the global title indicator (GTI). 3 possibles values are supported by the Eagle STP: •0 - no global title included •2 - global title includes translation type only •4 - global title includes translation type, numbering plan, encoding scheme, nature of address • Bit 7: Indicates if subsequent GT translations are required •0 – Called also GT, indicates that a subsequent translation must be performed •1 – Called also SSN, indicates that no further translations are required • Bit 8: Reserved and not used in ITU

14

Structure of the CDPA 

Following octets of the CDPA 8

7

6

5

4

3

2

1

PC (if present) SSN (if present) TT NP

ES NAI

GTA

Digit 2

Digit 1

Digit 4

Digit 3

Digit 6

Digit 5

Digit 8

Digit 7

… Tekelec Confidential

‘07 | 15

Notes • In ITU the PC is rarely present in the CDPA also the second octet of the CDPA is the SSN if it is present • SSN is the value of the application used to query its associated database • TT is the Translation Type. Mostly equal to 0 in ITU • NP is the Numbering Plan of the following GTA in the CDPA. Could be E164, E214 or E212 • ES is the Encoding Sheme of the following GTA in the CDPA. Always equal to BCD encoding in ITU • NAI is the Nature Address Indicator of the following GTA in the CDPA. Could be Subscriber, National or International • GTA part contains the dialed number. The BCD encoding is used. That means that one octet contains 2 digits of the number

15

Global Title Indicator (GTI) 



2 configurations are possible in ITU Depending on the value of the GTI, different fields are extracted to perform GTT NI

RI

GTI=4

SSN

PC

NI

RI

GTI=2

SSN

SSN

TT

TT

NP

ES

NP

NAI

SSN

PC

ES NAI

Digit 2

Digit 1

Digit 2

Digit 1

Digit 4

Digit 3

Digit 4

Digit 3

Digit 6

Digit 5

Digit 6

Digit 5

Digit 8

Digit 7

Digit 8

Digit 7


‘07 | 16

Notes •The GTI=4 is the most used one in ITU because in ITU TT=0 in most of case also other f ield need to be extracted to interpret the GTA

16

GTT Tables 

Extracted fields from CDPA are used to lookup the corresponding table to translate the GTA to DPC (and SSN if possible and if required)

GTI=4, TT=0, NAI=NATL, NP=E164, ES=BCD

GTI=4, TT=0, NAI=INTL, NP=E164, ES=BCD

Table1

Table2

GTA:06070000 DPC: 5000 RI:gt

GTA:336070000 DPC: 111 RI:gt

GTA:06071111 DPC: 6000 RI:gt

GTA:336071111 DPC: 222 RI:gt

…

…


‘07 | 17

Notes

17

Example of GTT TRANSMISSION DIRECTION

MSU sent by the SSP to the STP

MTP3 Fields

SCCP Fields

…

CDPA

NI=0 RI=0

DPC=1500

NI=2

SI=3

GTI=4

SSN=1 PC=0

…

SSN=253 TT=0

1000

NP=E164 SSP

ES=BCD

NAI=NATL

STP 1500


Digit 2=8

Digit 1=0

Digit 4=0

Digit 3=0

Digit 6=4

Digit 5=3

Digit 8=0

Digit 7=5


‘07 | 18

Notes • The SSP doesn’t have in its MTP3 routing table another SSP or Switch where to route this call • The SSP must build an INAP query and uses its SCCP routing table to send it to the STP with the Point Code 1500

18

Example of GTT 



The STP with the PC 1500 performs GTT depending on the information extracted from the incoming MSU This information is used to lookup the corresponding table to translate the GTA to a DPC (SSN is already known in this example and does not need to be looked up) GTI=4, TT=0, NAI=NATL, NP=E164, ES=BCD

STP

GTT is done in the STP

1500

Table1 GTA:0800345 DPC: 2000 RI:gt … Tekelec Confidential

‘07 | 19

Notes • As RI=gt that mean this STP perform Intermediate GTT

19

Example of GTT TRANSMISSION DIRECTION

MSU sent by the STP to the next STP

MTP3 Fields

SCCP Fields

…

CDPA

NI=0 RI=0

DPC=2000

NI=2

SI=3

GTI=4

SSN=1 PC=0

…

SSN=253 TT=0 NP=E164 STP 1500

ES=BCD

NAI=NATL

STP 2000


Digit 2=8

Digit 1=0

Digit 4=0

Digit 3=0

Digit 6=4

Digit 5=3

Digit 8=0

Digit 7=5 ‘07 | 20

Notes

20

Example of GTT 



The STP with the PC 2000 performs GTT depending on the information extracted from the incoming MSU This information is used to lookup the corresponding table to translate the GTA to a DPC (SSN is already know in this example and does not need to be looked up) GTI=4, TT=0, NAI=NATL, NP=E164, ES=BCD

STP

GTT is done in the STP

2000

Table1 GTA:0800345 DPC: 3000 RI:ssn … Tekelec Confidential

‘07 | 21

Notes • Ri=ssn means this STP perform Final GTT • As the SSN is already into the MSU, this STP don’t have to fill this information into the MSU to perform Final GTT

21

Example of GTT MTP3 Fields

SCCP Fields


…

MSU sent by the STP to the next STP

CDPA

NI=0 RI=1

DPC=3000

NI=2

SI=3

GTI=4

SSN=1 PC=0

…

SSN=253 TT=0

STP 2000

SCP

NP=E164

SSN 253

ES=BCD

NAI=NATL

3000


Digit 2=8

Digit 1=0

Digit 4=0

Digit 3=0

Digit 6=4

Digit 5=3

Digit 8=0

Digit 7=5 ‘07 | 22

Notes

22

CGPA 









To be enable it to receive a response from the requested database the originating node (SSP in the previous example) inserts its GTA address in the CGPA of the SCCP field of the MSU This means all nodes are identified by a PC and an SCCP address (called node ID) The structure of the CGPA is exactly the same as the CDPA Normally the Node Initiating the query inserts the CGPA of the originating SSN into the SSN field of the CGPA

To route the response, the final SCP node switches the CDPA & CGPA and uses SCCP routing to respond to the originating node


‘07 | 23

Notes

23

CGPA: SSP builds an INAP query MTP3 Fields

SCCP Fields


…

MSU sent by the SSP to the next STP

CGPA

NI=0 RI=0

…

DPC=1500

NI=2

SI=3

GTI=4

SSN=1 PC=0

SSN=250 TT=0 NP=E164

NAI=NATL

1000 250

SSP STP 12345678

ES=BCD

1500

Digit 2=2

Digit 1=1

Digit 4=4

Digit 3=3

Digit 6=6

Digit 5=5

Digit 8=8

Digit 7=7


‘07 | 24

Notes

• When an SSP build an INAP query an SSN on the SSP is specified

24

CGPA: MSC/VLR sends an Update Location MTP3 Fields

SCCP Fields


…

MSU sent by the MSC/VLR to the next STP

CGPA

NI=0 RI=0

…

DPC=1500

NI=2

SI=3

GTI=4

SSN=1 PC=0

SSN=7 TT=0 NP=E164

NAI=NATL

1100 7

MSC STP 12345666

ES=BCD

1500 Tekelec Confidential

Digit 2=2

Digit 1=1

Digit 4=4

Digit 3=3

Digit 6=6

Digit 5=5

Digit 8=6

Digit 7=6 ‘07 | 25

Notes

• When an MSC/VLR send an Update Location, the SSN of the VLF (7) is put into the SSN field of the CGPA of the MSU

25

MTP3 & SCCP routing within the Eagle STP


‘07 | 26

Notes

26

MTP3 Routing in the Eagle STP

IMT Bus

Routing MTP Routing

Step 3

Discrimination

Step 2

Level 2

Step 1

SS7 Card 1201

SS7 Card 1301

Port A or B

Port A or B

incoming ISUP MSU

outgoing ISUP MSU


‘07 | 27

Notes • In the SS7 card 1201

• Step1: MTP2 error checking is performed to check the MSU is not corrupted • Step2: Discrimination means extract the SI field from the MTP3 portion of the MSU to identify the type of the incoming MSU. In this example SI=5 means ISUP MSU. That means this MSU just need to be MTP3 routed • Step3: The SS7 card has a copy in her memory of the routing table stored in the TDMs. With the DPC of the MSU, the SS7 card is so able to route the MSU to the next node. A link has been chosen and the card where this link is plugged is also identified • In the SS7 card 1301: The MSU is just routed on the chosen link

27

SCCP Routing in the Eagle STP

IMT Bus

Routing Distribution

Step 3

GTT Tables

Step 4

Discrimination

Step 2

routing table

Step 5

linkset table

Step 6

slk table

Step 7

Level 2

SS7 Card 1201

Step 1

DSM-VSCCP 1203

Port A or B

SS7 Card 1301 Port A or B

incoming SCCP MSU

outgoing SCCP MSU


‘07 | 28

Notes • In the SS7 card 1201 • Step1: MTP2 error checking is performed to check the MSU is not corrupted • Step2: Discrimination means extract the SI field from the MTP3 portion of the MSU to identify the type of the incoming MSU. In this example SI=3 means SCCP MSU. That means this MSU must be translated by using GTT to find the PC of the next node • Step3: The SS7 card use the method of « Ticket Voucher Group » to find a DSM card available to perform this GTT and send her the MSU • In the DSM card 1203 • Step4: GTT is performed • Step5: The DSM card has a copy in her memory of the routing table stored in the TDMs. With the translated DPC (given by GTT) of the MSU, the DSM card find out a linkset in the routing table to reach that DPC • Step6: The linkset table is used to choose a link inside this linkset by using SLS rotation on 4bits in ITU • Step7: The slk table is used to find out the SS7 card where the chosen link is plugged • In the SS7 card 1301: The MSU is just routed on the chosen link

28

Configuration of GTT in the Eagle STP


‘07 | 29

Notes

29

GTT and EGTT features 







Whereas in ANSI networks the GTT feature of the Eagle STP is sufficient, in ITU it is not as the TT field of CDPA is never used to identify a translation table and additional selectors are required This is why the EGTT feature must be activated in ITU networks to increase the number of selectors EGTT provides some additional functions during the processing of gtt which are compliant with the ETSI recommendations To activate a feature the following command is used: • CHG-FEAT:GTT=ON



To activate EGTT the feature GTT must already be set to ON • CHG-FEAT:EGTT=ON



When these features are ON it is not possible to turn them back OFF Tekelec Confidential

‘07 | 30

Notes

• Number of Selectors means extract other fields from the CDPA than only the TT field • EGTT provide some additional features defined in the ETSI norm: • Deletion of GT • Insertion of the SSN into the CDPA • Insertion of the OPC into the CGPA • EGTT will not check for the presence of gaps in the message length • EGTT allows routing of ITU messages without SSN

30

Example of configuration from scratch 

Two configurations must be created (one on each STP) to allow SSP 1000 to reach the database 253

1000

SSP STP 1500

STP 2000

SCP

SSN 253

3000



‘07 | 31

Notes

31

Example of configuration: for STP 1500 



STP 1500 will perform an Intermediate GTT. The first step is to create the table that will contain the GTAs. The command is: ENT-GTTSET:GTTSN=TABLE1:NETDOM=ITU:NDGT=7

Number of digits in the GTAs contained in this table

The name of the table To specify the domain of the GTAs contained in the table


‘07 | 32

Notes • All the GTAs from the defined table must have the same number of digits specified by the NDGT parameter • One GTTSET is a bunch of GTA values

32

Example of configuration: STP 1500 





When the Eagle STP extracts information from the CDPA, this information is used to find a match with the defined selectors The second step is to create the selector that will specify which GTTSET table will be used to lookup the GTA and find the translation information The command is: ENT-GTTSEL:GTIN=4:TT=0:NP=E164:NAI=NATL:GTTSN=TABLE1

The “N” means national but ITU doesn’t make any differentiation between national and international

If the CDPA of the MSU contains these values, then table=TABLE1 will be used to translate the GTA

Table created on the first step


‘07 | 33

Notes • The Eagle STP knows if the MSU comes from a National or International Linkset according the NI field from the MTP3 portion of the MSU • GTII is not used on ITU GTIN is enough as ITU doesn’t make any difference between national and international into the SCCP part. • When a selector match, the GTA digits f rom the CDPA is decoded and his length is compared to the NDGT parameter of the corresponding table • If length of GTA < NDGT => error • If length of GTA > NDGT => use leading ndgt on GTA • Note the ES field from the CDPA is never used by an Eagle Command. This value is used internally by the Eagle to extract the GTA digits from the CDPA • The GTTSET command must be entered in the configuration of the Eagle before the GTTSEL command because of the GTTSN parameter • One GTTSET table can have several GTTSEL selectors linked to it • It is not possible to have 2 GTTSEL selectors with the same value for GTI, TT, NP and NAI (to avoid confusion)

33

Example of configuration: STP 1500 

The last step is to enter the GTA into the existing table. The command is:



ENT-GTA:GTTSN=TABLE1:GTA=0800345:RI=GT:XLAT=DPC:PCN=2000

The result of the translation is a PC The name of the table

GTA we add to this table

To define Intermediate GTT is performed


The value of the PC

‘07 | 34

Notes • RI parameter equal SSN in case of a Final GTT • XLAT parameter define what the result of the GTT is. It could be: •DPC: means only the PC of the next node is defined •DPCSSN: means the PC of the next node is defined and the SSN of the final node which is requested will be fill into the CDPA. In this case the SSN parameter must be used with the command ent-gta •NGT: means New Global Title. Only the field TT of the CDPA portion can be changed • PCN : means Point Code National. If the result of the translation is an International Point Code, the parameter PCI will be used instead of PCN • The GTA length must be between 1 and 21 (1 and 21 included)

34

Example of configuration: for STP 2000 

STP 2000 will perform a Final GTT. The commands to be entered into this STP are:



ENT-GTTSET:GTTSN=TABLE1:NETDOM=ITU:NDGT=7



ENT-GTTSEL:GTIN=4:TT=0:NP=E164:NAI=NATL:GTTSN=TABLE1



For Final GTT before using the ENT-GTA command, another step is required to define the mated applications


‘07 | 35

Notes • ENT-MAP command configure a solitary mode

35

SCCP Network Management Messages


‘07 | 36

Notes

36

SCCP Network Management Messages 

When an application on a node becomes unavailable the node sends an SSP to the adjacent points code to inform them the database is no longer reachable SSP

SCP 253

STP

3000

2000 

When the application is back up again, the node sends an SSA to the adjacent point codes to inform them the database is now reachable again SSA

SCP 253

STP

3000

2000


‘07 | 37

Notes • SSP stands for SubSystem Prohibited • SSA stands for SubSystem Allowed

37

Mated Application for Final GTT


‘07 | 38

Notes

38

Mated Applications: MAP Table 





Mated application is used for Final GTT only and is done by accessing the MAP Table in the Eagle STP In the MAP table an application on a node can be associated with up to 32 other applications on other nodes As for the MTP3 routing, the parameter RC is used to configure the relation between an application on a node with the other applications on other nodes. 4 possible configurations: • • • •

Solitary Mode Dominant Mode Load Sharing Mode Combined Dominant / Load Sharing Mode


‘07 | 39

Notes • RC means Relative Cost • When a PC/SSN pair is not replicated, the pair is in solitary mode. The subsystem acts as the only application, with no backup. If this subsystem fails, messages routed to it are discarded and SCCP management returns “Subsystem Unavailable” messages to the originator • A group of replicated PC/SSN pairs are in dominant mode if each PC/SSN pair in the group has a unique relative cost. The specified subsystem acts as the primary point code/subsystem, while the mate point code/subsystem acts as a backup. In the event of congestion, messages route to the mate point code/subsystem. When the congestion subsides, messages are again routed to the primary (dominant) point code/ subsystem • A group of replicated PC/SSN pairs are in load sharing mode if each point code/SSN pair in the group has the same relative cost. All messages are evenly distributed at the SCCP level to both point code/subsystems in the group. In the event of congestion or failure, the non-affected subsystem assumes the load of its failed or congested mate • The combined load sharing/dominant mode supports a combination of load sharing and dominant mode. A group of PC/SSN pairs are in combined load sharing/dominant mode when at least two of the point code/SSN pairs have the same relative cost and another node subsystem in the group has a different relative cost

39

Mated Applications: Example 



In many cases applications are deployed in pairs for security and reliability reasons. If a database is not reachable, the request can be processed by using a mated application node An example of Load Sharing Mode between 2 applications on 2 nodes 1000

(25) Queries

SSP (50) Queries

STP

SCP 253 3000

2000 (25) Queries

SCP 253 4000 Tekelec Confidential

‘07 | 40

Notes

40

Mated Applications: Example 

To configure the previous example on the Eagle STP the command is: Translated PC after Final GTT and the SSN value contained in the MSU after Final GTT



ENT-MAP:PCN=3000:SSN=253:RC=50:MPCN=4000:MSSN=253:MATERC=50

The value of the PC

The value of the application

Relative cost of this couple (PC, application)

Values of the mated couple (PC,application)


‘07 | 41

Notes • Same as for the command for GTT PCN stands for Point Code National. PCI will be used instead if an International Point Code need to be configured • The Mated Applications configuration is not explicitly defined in the command. It is the relative cost values define the configuration applied (Dominant, Load Sharing or Combined) • With a command ent-map only 2 mated applications can be entered in the same time. As we can go up to 32 mated applications we have to enter the command again with the PC and SSN of the result of Final GTT and the new couple (PC, application). For example to add a third PC and Application to this Load Sharing configuration the command would be: ENTMAP:PCN=3000:SSN=253:RC=50:MPCN=5000:MSSN=253:MATERC=50

41

Mated Applications 



Before entering the ENT-GTA command, the DPC of the Final Destination must have been entered into the MAP table with the ENTMAP command When a Final GTT is performed on an MSU, before sending this MSU to the translated DPC and the SSN of the Final Destination, a lookup is done in the MAP table to apply for the mated application configuration associated to the translated DPC


‘07 | 42

Notes

42

Example of configuration: STP 2000 (end) 

The configuration of STP 2000 can now be completed:



ENT-MAP:PCN=3000:SSN=253:RC=99



ENT-GTA:GTTSN=TABLE1:GTA=0800345:RI=SSN:XLAT=DPC:PCN=3000





After entering both these GTT configurations the database associated with SSN 253 can be requested But at this stage the response can’t be returned to the initiating SSP…


‘07 | 43

Notes • ENT-MAP command in this example configure a solitary mode

43

Concerned Signaling Point Code (CSPC)


‘07 | 44

Notes

44

CSPC definition 



A CSPC is an STP performing Final GTT that doesn’t have adjacent links to the final destination STPs which have adjacent links to the final destination have to broadcast SCCP Network Management Messages to inform the CSPC STPs about SSP or SSA 1000

STP

3000

STP

SCP 253 Subsystem Prohibited (SSP)

STP 2000

STP

SCP 253


‘07 | 45

Notes

45

CSPC example in STP 3000 



A CSPC Table can be created in the Eagle STP to add these CSPCs. The command is: ENT-CSPC:GRP=GROUP1 First the list of CSPCs must be created



Then ENT-CSPC:GRP=GROUP1:PCN=1000 ENT-CSPC:GRP=GROUP1:PCN=2000



In this example the same configuration must be entered into STP 4000





Each CSPC is inserted to the created list (Group 1 in this example)


‘07 | 46

Notes • A maximum of 32 concerned point codes per group and a maximum of 2549 groups are possible in this table • The point code entered must exist in the Eagle's routing tables and cannot already exist in the specified group

46

CSPC example 

The result is: CSPC Table GRP=Group1 PC=1000 PC=2000

3000

1000

STP

STP

SCP 253 Subsystem Prohibited (SSP)

STP

STP

2000

SCP 253

4000 CSPC Table GRP=Group1 PC=1000 PC=2000


‘07 | 47

Notes

47

Variable GTT


‘07 | 48

Notes

48

VGTT Feature 







VGTT feature gives some flexibilities for the GTT configuration All entries in a list of GTAs (GTTSET) must have the same length depending on the value of parameter NDGT when a GTTSET list is created With VGTT feature the NDGT parameter no longer has to be specified and each list can contain GTAs of different lengths Up to 10 different GTA lengths are allowed in each GTTSET


‘07 | 49

Notes

49

VGTT Feature 

To activate VGTT the feature GTT and EGTT must already be set to ON. Then to activate VGTT the command is: • CHG-FEAT:VGTT=ON



When VGTT is set to ON it can’t be set back to OFF


‘07 | 50

Notes

50

VGTT Feature example 

Example of different GTA lengths in the same GTTSET • ENT-GTTSET:GTTSN=TABLE1:NETDOM=ITU

The NDGT parameter doesn’t need to be specified

• ENT-GTTSEL:GTIN=4:TT=0:NP=E164:GTTSN=TABLE1 Example of range of GTAs

• ENTGTA:GTTSN=TABLE1:GTA=080040:EGTA=080050:RI=GT:XLAT=DPC:PC N=1500 • ENTGTA:GTTSN=TABLE1:GTA=0800555100:RI=GT:XLAT=DPC:PCN=1500 GTA of 6 digits and GTA of 10 digits Tekelec Confidential

‘07 | 51

Notes

51

Intermediate GTT Load Sharing


‘07 | 52

Notes

52

IGTTLS Feature 



IGTTLS feature is an additional feature to allow load sharing for STPs performing Intermediate GTT It works in the same way as the Mated Application for STPs performing Final GTT



Final GTT uses MAP Table whereas Intermediate GTT uses MRN Table



In the MRN table a node can be associated with up to 32 other nodes



As for the MTP3 routing, the parameter RC is used to configure the relation between a node and other adjacent nodes. There are 3 possible configurations: • Dominant Mode • Load Sharing Mode • Combined Dominant / Load Sharing Mode Tekelec Confidential

‘07 | 53

Notes • MRN stands for Mated Relay Node

53

IGTTLS Feature 

Example of dominant configuration on STP 1000 3000

1

STP

1000

STP

2

STP 3

2000

4000 5000

STP

STP

SCP 253

SCP 253

4

STP 6000 Tekelec Confidential

‘07 | 54

Notes

54

Example of IGTTLS on STP 1000 







The first step is to activate the IGTTLS feature The IGTTLS feature is not a feature like GTT, EGTT or VGTT. It is a Control Feature, meaning it is protected by a Feature Access Key (FAK) The command to enable this feature is: ENABLE-CTRL-FEAT:partnum=893006901:fak=CDXHSAN6PHKTE Tekelec Identifier of this feature





Unique & valid only for this STP

The command to activate this feature is: CHG-CTRL-FEAT:partnum=893006901:status=ON Activate the feature

Tekelec Identifier of this feature


‘07 | 55

Notes • The FAK is computed according the Serial Number of the Eagle STP and is so valid only on that corresponding Eagle STP • IGTTLS can be turned off (mean the MRN Table will no more be lookup) with the following command: •CHG-CTRL-FEAT:partnum=893006901:status=ON

55


Then type the command to enter the configuration into the MRN table:



ENT-MRN:PCN=3000:RC=10:PCN1=4000:RC1=20:PCN2=5000:RC2=30



With the RC parameter for each PC defined, the dominant mode has been configured



The GTT will be configured as following:



ENT-GTA:GTTSN=TABLE1:GTA=0800345:RI=GT:XLAT=DPC:PCN=3000



After the GTT and before sending the defined the MSU to node 3000, the MRN Table is accessed to find a match with PC 3000 • If no match is found, the MSU is sent to PC 3000 • If a match is found, the associated configuration is applied. In this example, if PC 3000 is reachable, the MSU is sent there


‘07 | 56

Notes • In Dominant Mode if the PC designed by the GTT is not available, the next highest value of RC is choosen to send the MSU to the corresponding PC with this RC. If this one is also not available the process continue as the same way • It is possible to define in the GTT that the translated DPC doesn’t match with the smallest RC in the MRN table associated with this PC. The MSU is anyway sent to this choosen DPC and if it is not available the next highest is choosen (not the smallest one)

56


To add the latest STP to this MRN group:



CHG-MRN:PCN=3000:PCN1=6000:RC1=40

Enter one PC of the group

Add the PC with its RC to this group


‘07 | 57

Notes

57

Limitations of IGTTLS 





Eagles will not guarantee correct MSU sequencing when Load Sharing is used. MSUs with the same SLS values values may be sent to different different nodes nodes Any given point code can be part of only one point code group, i.e., any point code entered entered as part of a point code group cannot later later be made part of a different point code code group, unless it is first deleted deleted from the initial group An MRN group can contain up to 32 alternate point codes, that can be used for load sharing between multiple nodes


‘07 | 58

Notes • 32 altern alternate ate point codes codes since since the release release 36.0 36.0 of the Eagle. Eagle. Only Only 8 alternat alternate e point codes before before this version version

58

Flexible Load Sharing


‘07 | 59

Notes

59

Flexible Intermediate GTT LS Example

2000 1000

STP STP MRNSET1 Table (Dominant Mode)

MRNSET2 Table (Load Sharing Mode)

PCN= 2000

PCN= 2000

RC=10

RC=20

PCN= 3000

PCN= 3000

RC=20

RC=20

STP 3000

GTA Table GTA=999999 PCN= 2000 MRNSET=MRNSET1 GTA=999998 PCN= 2000 MRNSET=MRNSET2


‘07 | 60

Notes

60

Flexible Final GTT LS Example

4000 2000

SCP 253

STP MAPSET1 Table (Dominant Mode)

MAPSET2 Table (Load Sharing Mode)

PCN= 4000 SSN=253

PCN= 4000 SSN=253

RC=10

RC=20

PCN1= 5000 SSN=253

PCN1= 5000 SSN=253

RC1=20

RC1=20

SCP 253 5000

GTA Table GTA=999999 PC= 4000 SSN=253 MAPSET=MAPSET1 GTA=999998 PC= 4000 SSN=253 MAPSET=MAPSET2


‘07 | 61

Notes

61

Origin Based SCCP Routing


‘07 | 62

Notes

62

Origin Based SCCP Routing Example

1100 999999

4000 2000

MSC

SCP 253

STP SCP 253

MSC 1200 999998

GTA Table

5000

GTA=9194602000 EGTA=9194602200 PC= 4000 SSN=253 XLAT=DPCSSN RI=SSN idx=1 Advanced GTA Table idx=1 CGPA=999998 PC= 5000 SSN=253 XLAT=DPCSSN RI=SSN


‘07 | 63

Notes • For the same mobile when 2 differents MSCs queries an SCP the result of GTT is not the same: • For MSC 999999 the GTA table indicate the PC of the SCP 4000. An advanced index exist so the Advanced GTA table must be check. No match is found so the query is sent to the SCP 4000 • For MSC 999998 the GTA table indicate the PC of the SCP 4000. An advanced index exist so the Advanced GTA table must be check. A match is f ound so the query is sent to the SCP 5000

63

Weighted GTT Load Sharing


‘07 | 64

Notes

64

Weighted GTT Load Sharing Example 

Example of Final GTT

4000

SCP 253

2000

SCP 253

STP MAPSET1 Table (Combined Dominant / Load Sharing)

5000

PC= 4000 SSN=253 RC=10 WEIGHT 70 THR 60

6000

PC= 5000 SSN=253 RC=10 WEIGHT 30 PC= 6000 SSN=253 RC=20 WEIGHT 60 THR 40

SCP 253

PC= 7000 SSN=253 RC=20 WEIGHT 40

SCP 253

GTA Table GTA=999999 PC= 4000 SSN=253 MAPSET=MAPSET1


‘07 | 65

Notes • Works for Intermediate GTT in the same way. In this case MAPSET is replaced by MRNSET • In normal mode the traffic is load shared between PC 4000 and PC 5000: •4000 will carry 70% of the traffic •5000 will carry 30% of the traffic • ISWT means In-Service Weight Threshold which means in this example that at least 60% of the traffic must be carry by this RC. If not the other RC will be use (RC=20 in this example) • If the linkset to 4000 is down, only 30% of the traffic can be carry through 5000, that’s not enough because the threshold is 60% so traffic will be load shared between 6000 and 7000 • 6000 will carry 60% of the traffic • 7000 will carry 40% of the traffic

65

Transaction Based GTT Load Sharing


‘07 | 66

Notes

66

Modified GTT


‘07 | 67

Notes

67

Rept-stat-sccp


‘07 | 68

Notes

68

TK155 ITU .pdf

Recommend Documents