Common Channel Signaling.pdf

7/27/2019 Common Channel Signaling.pdf

1/15

Optimizing MTP configuration.

Modifying MTP level 3 signaling parameters

Modifying SS7 signaling network parameters

Modifying the values of signaling link parameter set

Creating new signaling link parameter set

Modifying the values of signaling route set parameter set

Creating new signaling route set parameter set

Setting and modifying MTP level signaling traffic restrictions

Modifying MTP level signaling traffic load sharing

Using the signaling link set of another signaling network

Removing MTP signaling point

Moving a BSC under another MSC


2/15

Common Channel Signaling (MTP, SCCP and TC) Optimizing MTP configuration

6 Optimizing MTP configuration

After the initial setup, you can optimize your MTP configuration by:

modifying the MTP level 3 signaling parameters

modifying the SS7 signaling network parameters modifying the signaling link parameter set

modifying the signaling link route parameter set

setting/modifying the MTP level signaling traffic restrictions

modifying the MTP level signaling traffic load sharing

using the signaling link set of another signaling network

removing the MTP signaling point

6.1 Modifying MTP level 3 signaling parameters

MTP level 3 signaling parameters define the functions of the whole MTP of the

network element. Some of the parameter values are related to monitoring the

functions, while others define various limits and timers.

Modify the values of these parameters when you think that some of the MTP level

3 timers values are not suitable.

Before you start

As MTP level 3 parameters affect the whole network element's SS7 signaling,

make sure that the change will not cause any malfunctions in the signaling system.

In most cases, the predefined parameters are the most suitable ones.

Steps

1 Check MTP level 3 parameters (NMI)

You can display the used parameter values grouped by parameter sets with the

NMI command.

2 Modify MTP level 3 parameter (NMM)

ZNMM: : =;

6.2 Modifying SS7 signaling network parameters

SS7 signaling network parameters apply to the whole signaling network. This means

that SS7 signaling network parameters can be separately defined for each signaling

network (NA0, NA1, IN0, and IN1).

Before you start

As SS7 signaling network parameters affect the whole signaling network, make sure

that the change will not cause any malfunctions in the signaling system.

In most cases predefined parameters are the most suitable ones.


3/15

Optimizing MTP configuration Common Channel Signaling (MTP, SCCP and TC)

Steps

1 Check parameter values (NMO)

You can display the used parameters in each signaling network with the NMOcommand.

2 Modify SS7 signaling network parameters (NMC)

ZNMC: : : =;

6.3 Modifying the values of signaling link parameter set

The parameters in the signaling link parameter set define the function of the signaling

link. You can create several signaling link parameter sets for different types of

signaling links. Each signaling link uses the signaling link parameter set attached to it.

Before you start

As the signaling link parameters affect all the signaling links which use that certain

sig-naling link parameter set, make sure that the change will not cause any

malfunctions in the signaling system.


g If you change the values of an existing signaling link parameter set, you have to deacti-vate allthe signaling links using that particular parameter set. This means that all sig-naling traffic inthese signaling links stops and all calls using these signaling links will be cut.

The best way to modify signaling link parameters is to create a new parameter set

and attach it, one by one, to each signaling link. This procedure is useful when a new

network element is taken into use but is not used for the actual call transmission.

Steps

1 Check signaling links and the parameter sets they use (NCI)

As the modifying of the values of an existing parameter set affects all signaling links using

that signaling link parameter set, check whether this can be done. If you want only a

certain group of signaling links to have different signaling link parameter values, you

should create a new signaling link parameter set and attach it to those signaling links.

You can output all signaling links and the signaling link parameter sets they use with

the NCI command.

2 Deactivate signaling li nks using the parameter set you want to modify (NLC)

The new values of the parameter set become active when the signaling links that

use the parameter set are first deactivated and then they are activated again.

ZNLC: , I NA;


4/15


3 Modify values of signaling link parameter set (NOM)

ZNOM: , , : , ;

4 Acti vate signaling li nks using the modif ied parameter set (NLC)

ZNLC: , ACT;

6.4 Creating new signaling link parameter set

The parameters in the signaling link parameter set define the function of the signaling

link. You can create several signaling link parameter sets for different types of

signaling links. Each signaling link uses a signaling link parameter set attached to it.

Before you start

As the signaling link parameters affect all signaling links which use that certainsignaling link parameter set, make sure that the change will not cause any

malfunctions to the sig-naling system.


g If you change the values of an existing signaling link parameter set, you have to deacti-vate allsignaling links using the parameter set. This means that all signaling traffic in these signaling linksstops and all calls using these signaling links will be cut.

The best way to modify signaling link parameters is to create a new parameter set

and attach it, one by one, to each signaling link. This procedure is useful when a new

network element is taken into use but is not used for actual call transmission.

Steps

1 Check signaling links and the parameter sets they use (NCI)

You can output all signaling links and the signaling link parameter sets they are

using with the following command.

ZNCI ;

2 Copy existing s ignaling link parameter set with a new name (NOE)

The best way to create a new signaling link parameter set is to copy an old parameter

set with a new name. Choose the best suitable parameter set to be the source

param-eter set.

ZNOE: , : , ;


5/15


3 Modify values of the new signaling li nk parameter set (NOM)

ZNOM: , , : , ;

4 Deactivate the signaling links that you want to use with the new parameter

set (NLC)

It is reasonable to deactivate only a few of the signaling links at a time if you want

sig-naling traffic to be transmitted normally during the modification.

ZNLC: , I NA;

5 Change parameter set of signaling li nk (NCL)

Replace the existing parameter set of the signaling link with the new signaling

link parameter set.

ZNCL: : ;

6 Activate signaling link s using the new parameter set (NLC)

ZNLC: , ACT;

6.5 Modifying the values of signaling route set parameter set

The parameters in the signaling route set parameter set define the signaling route set

signaling functions. You can create several signaling route set parameter sets for

differ-ent types of signaling route sets. Each signaling route set uses a parameter set

for the signaling route set attached to it.

Before you start

As the signaling route set parameters affect all signaling route sets which use the

same signaling route set parameter set, make sure that the change will not cause any

mal-functions to the signaling system.

In most cases the predefined parameters are the most suitable ones.

Steps

1 Check signaling route sets and the parameter sets they use (NRI)

As the modification of the values of an existing parameter set affects all the signaling

route sets using that signaling route set parameter set, consider if this can be done. If

you want only certain signaling route sets to have different values in the signaling

route set parameters, you should create a new signaling route set parameter set and

attach it to those signaling route sets.

You can output all signaling route sets and the signaling route set parameter sets

they are using with the following command.

ZNRI : ;


6/15


If you only want to modify the values of a certain signaling route set parameter set,

continue to the next step, but if you want to create a new signaling route set

parameter set, continue with the procedure of .

2 Modify values of signaling rou te set parameter set (NNM)ZNNM: , , : =;

3 Deactivate signaling route sets using the modif ied parameter set (NVC)

The new values of the parameter set do not become active until the signaling route

set that uses the parameter set is first deactivated and activated again.

ZNVC: , : , : I NA;

4 Acti vate signaling route sets using the modi fied parameter set (NVC)

ZNVC: , : , : ACT;

6.6 Creating new signaling route set parameter set

The parameters in the signaling route set parameter set define the signaling route set

signaling functions. You can create several signaling route set parameter sets for

differ-ent types of signaling route sets. Each signaling route set uses a signaling route

set parameter set attached to it.

Before you start

As the signaling route set parameters af fect all the signaling route sets which use the

same signaling route set parameter set, make sure that the change will not cause

any malfunctions to the signaling system.

In most cases the predefined parameters are the most suitable ones.

Steps

1 Check signaling route sets and the parameter sets they use (NRI)

As the modification of the values of an existing parameter set affects all the signaling

route sets using that signaling route set parameter set, consider if this can be done. If

you want only certain signaling route sets to have different values in the signaling

route set parameters, you should create a new signaling route set parameter set andattach it to those signaling route sets.

You can output all the signaling route sets and the signaling route set parameter

sets they are using with the following command:

ZNRI : ;

If you just want to modify the values of a certain signaling route set parameter set,

continue with the procedure of , but if you want to create a new signaling route set

parameter set, continue with the next step.


7/15


2 Copy existing signaling route set parameter set with a new name (NNE)

The best way to create a new signaling route set parameter set is to copy an old

param-eter set with a new name. Choose the best suitable parameter set to be the

source parameter set.ZNNE: , : , ;

3 Modify values of the new signaling rou te set parameter set (NNM)

ZNNM: , , : =;

4 Change parameter set of signaling route set (NRB)

Replace the existing parameter set of the signaling route set with the new signaling

route set parameter set.

ZNRB: , : PARA=;

Further information

Example: Creating new s ignaling route set parameter set

With the following example, you can create a new signaling route set parameter set

with the name MIKA (number 7) by copying the existing parameter set number 0

(ITU-T). First, change the value of the parameter D2 (TFC_DENIED) to YES, then

change the signaling route sets in signaling network NA0 leading to signaling point

300 to use this parameter set.1. Check the signaling route sets and the parameter sets they use.

ZNRI : NA0;

2. Copy one of the existing signaling route set parameter sets with a new name.ZNNE: 0: 7, MI KA: ;

3. Modify the values of the new signaling route set parameter set.ZNNM: 7, MI KA, D: D2=Y: ;

4. Change the parameter set of the signaling route set.ZNRB: NA0, 300: PARA=7;

6.7 Setting and modifying MTP level signaling traffic restric-

tionsYou do not have to define the policing at the same time when configuring the

signaling network. You can do it later when you see how the network is working.

Plan the traffic restrictions that you need carefully.

Before setting any traffic restrictions, it is necessary to plan carefully what kind of

signal-ing traffic you want to allow and deny. Remember the following issues:


8/15


When signaling traffic is denied on the MTP level, the SCCP level signaling is also

denied.

If STP messages coming from a certain node are denied (not transferred), it is

possible that the node in question is not able to send any messages to any

direction (for example, when links to some other direction are down).

It is also possible to set the reports from STP traffic to check if traffic restrictions

are necessary.

To a direction where the Abis interface is used (that is, between BSC and BTS

network elements), there is no need to define any traffic restrictions (you can

check this with the NRI command).

When you want to change the existing traffic restrictions, it may be necessary to

remove some traffic restrictions.

The MTP level signaling traffic restrictions are defined between screening groups to

which signaling points can be assigned. Each of the two policing methods has two

types of screening groups (see the following table). A signaling point can only be a

member of one group of each type. When a new signaling point is created, it is

assigned to group number 0 in each screening group type.

Policing Screening Screening group definition Group

method group type number

A AASG Adjacent signaling point screening group 0-1023

Linkset/DPC ADSG Destination signaling point screening group 0-1023

method of adjacent SP policing method

O OOSG Originating signaling point screening group 0-1023

OPC/DPC ODSG Destination signaling point screening group 0-1023

method of OPC based policing

Table 3 Screening group types used in MTP level signaling traffic restrictions

Steps

1 Check existing signaling traffic restrict ion data (NRT)

When you modify signaling traffic restrictions, it is reasonable to first check the

existing restrictions to ensure that you remove the appropriate restrictions, and

consider what effects the removal of those restrictions have on your network.

Check the existing restriction data between screening groups.

ZNRT: ;

Check the members of screening groups.

ZNRT: : ;

2 Configure screening groups (NRB)

If needed, modify the MTP level screening groups. First, depending on the policing

method used, assign the adjacent/originating signaling points to an AASG or OOSG

group and then assign the destination signaling points to an ADSG or ODSG group.


9/15


ZNRB: , : =;

You can either assign signaling points to screening groups that already have

appropri-ate restrictions defined or assign the signaling points to empty screening

groups and then modify the restriction data between the groups.When you change the screening groups of a signaling point, remember to check if

the current groups have existing restrictions defined that need to be retained.

3 Modify signaling traffic restrict ion data (NRS)

Modify STP message treatment between AASG and ADSG, or OOSG and

ODSG screening groups.

ZNRS: : , : ;

gThe changes you make to the traffic restrictions between screening groups affect all the signaling points

that are members of the groups.

4 Check signaling traff ic restriction data (NRT)

ZNRT;

6.8 Modifying MTP level signaling traffic load sharing

With MTP level signaling traffic load sharing, you can share the signaling traffic

between signaling routes and between signaling links belonging to the same link set.

Within a signaling link set, load sharing is implemented in such a way that it automati-

cally covers all the links that are in active state. The priority of a signaling link does

not affect the load sharing system.

Load sharing between signaling routes takes effect only after you have allowed load

sharing by defining the same priority for all signaling routes and by allowing load

sharing in that route set.

Before you start

Before setting the load sharing, plan carefully which kind of load sharing is suitable

in the signaling network.

Steps

1 Check signaling rout e priorities and load sharing status (NRI)

ZNRI : , ;

2 Check MTP load sharing data (NEO)

Check which signaling links transmit each of the Signaling Link Selection (SLS) field

values. You can use this command to separately interrogate the load sharing data con-

cerning either the messages generated by the own signaling point or STP signaling


10/15


traffic (for example, for STP traffic according to the ANSI standards, the load sharing

system is different).

ZNEO: [ | def ] , [ | ] , [ | def ] : [ ( LI NK=[ | def ] ) | ( SLS=[ SLSout put >| def ] ) def ] ;

3 Modify signaling route pri ority if needed (NRE)

The priority can vary between 0 and 7, the primary priority being 7.

ZNRE: , : , , ;

4 Al low load shar ing in the s ignal ing route s et i f needed (NRB)

If you want to activate the load sharing and in the signaling route set in question it is

not already allowed (see the output of the NRI command), you have to change the

load sharing status.

ZNRB: , : LOAD=;

6.9 Using the signaling link set of another signaling network

If there is a need to use more than one network indicators (for example, NA0, NA1,

and IN0), it is possible to utilize the signaling link set of any other network.

This means that any signaling network can use the signaling link sets of any other

sig-naling network. In other words, there is a link set between two network elements

but there are two or more route sets using the same link set (for more information,

see example Using link set of another signaling network).

g The feature is valid only in classic mechanics. The feature can only be used between two Nokia Siemens Networks network ele-

ments.

This kind of arrangement is reasonable to use, for example, for backup connections

or when traffic between two network elements in a certain signaling network is low.

Steps

1 Create own signaling point to the signaling network which uses the signaling

link set of another signaling network (NRP)ZNRP: , , , : STAND=: : ;


11/15


2 Create signaling route set to the signaling network which uses the signaling

link set defined for anoth er signaling network (NRC)

ZNRC: , , , , , : , , , ;

3 Create route set to the destination point like normal STP route (NRC)

ZNRC: , , , , , : , , , ;

Further informationExample: Using link set of another signaling network

The following example shows how and when it is useful to use a link set of

another network.

SP A SP B SP C

NA0: NA0:SP=123 SP=234

NA1: NA1: NA1:SP=1123 SP=1234 SP=1456

SP signaling point

Figure 22 Example network where one network element belongs to two signaling

networks (NA0 and NA1)

The example network consists of the following network elements:

signaling point A, the SPC of which in NA0 is 123 and in NA1 is 1123

signaling point B, the SPC of which in NA0 is 234 and in NA1 is 1234

signaling point C, the SPC of which in NA1 is 1456.

In the example, network element C operates only in network NA1. Network elements

A and B are mainly working in network NA0, though they have some traffic in network

NA1. Signaling traffic from A to C is so low that it is not economical to configure a linkand link set also to network NA1 between A and B. In this case, it is possible to utilize

the link set defined for NA0 between A and B for NA1 network traffic as follows:

1. Create an own point to the NA1 signaling network in SP A:

ZNRP: NA1, 1123, S1123, STP: STAND=I TU- T: 1: ;

2. Create a route set in the NA1 network to SP B. This uses the link set defined for NA0:

ZNRC: NA1, 1234, S1234, 0, D, N: NA0, 234, SP234, 7;


12/15


3. Create a route set to SP C as a normal STP route:

ZNRC: NA1, 1456, S1456, 0, D, N: NA1, 1234, S1234, 7;

6.10 Removing MTP signaling point

This procedure describes how to remove an MTP signaling point.You can follow these

steps also when you only want to remove certain signaling links, signaling routes, or

sig-naling route sets.

Before you start

Before removing MTP level signaling configuration, the upper level user parts

(for example, SCCP) have to be removed.

Steps

1 Deactivate the signaling route (NVC)

ZNVC: NA0, 312: : I NA;

2 Deny the activation of the signaling route (NVD)

ZNVD: NA0, 312;

3 Deactivate the signaling links (NLC)

ZNLC: 12&13, I NA;

4 Deny the activation of si gnaling l inks (NLD)

ZNLD: 12&13;

5 Delete signaling route set (NRD)

ZNRD: NA0, 312, BSC2;

6 Delete TDM signaling links

a) Delete signaling links from the link set (NSR)

Delete the signaling links from the link set with the NSR command. The last

link cannot be deleted this way.

b) Delete the last link by deleting the link set (NSD)

Delete the last link from the link set by deleting the link set with the NSDcommand.

c) Delete signaling links (NCD)

ZNCD: 12;

7 Delete IP signaling links (op tional)

a) Delete the signaling link set (NSD)

Delete the signaling link set with the NSDcommand.

b) Remove the unused association set (OYD)ZOYD: ;


13/15


6.11 Moving a BSC under another MSC

If you need to move your BSC network element under another MSC, you do not have to

remove the existing signaling configuration from the BSC: there is a special command for

this operation. With this command, it is possible to change the Destination Point Code

(DPC) of the MTP and SCCP while the whole routing and speech circuits exist.

g You can use this command only in the BSC. For the changes to take effect, the network element has to berestarted.

Steps

1 Prepare the state o f the MTP (NVC, NVD, NLC, NLD)

Deactivate the signaling route set:

ZNVC: , : , : I NA;

Deny the activation of the signaling route set:

ZNVD: , : , ;

Deactivate signaling links:ZNLC: , I NA;

Deny the activation of signaling links:ZNLD: ;

2 Deactivate the signaling traffic of the SCCP (NGC)

ZNGC: , : I NA;

3 Output the results of the MTP and SCCP statistics concerning the old SPC,

if needed (OSD)

To stop and result all statistical reports, use the following command:

ZOSD: REP: ;

4 Execute the exchanging o f the adjacent signaling poin t code command (NRX)

Change the destination point code (DPC):

ZNRX: : , : , : ;

5 Acti vate MTP (NLA, NLC, NVA, NVC)

Allow the activation of the signaling links:

ZNLA: ;

Activate the signaling links:ZNLC: , ACT;

Allow the activation of a signaling route set:ZNVA: , : , ;


14/15


Activate the signaling route set:

ZNVC: , : , : ACT;

6 Acti vate the SCCP (NGC)

ZNGC: , : ACT;

7 Restart the BSC (USS)

ZUSS: SYM: C=DSK;

8 Verify the new network configuration (NRI, NSI, NGI, RCI)

Interrogate the data of the route set:

ZNRI : ;

Interrogate the data of the link set:

ZNSI : ; Interrogate the data of the SCCP:

ZNGI : ;

Interrogate the data of circuits:ZRCI : ;

Further information

Example: Moving a BSC under another MSC

The following procedure (with the command examples) presents how to use this feature.

In the example, the network element BSC2 under MSC1 is moved under MSC2.

The example network is the same as the one previously used in the MTP

configuration. The example commands are given in BSC2.

MSC2 MSC2NA0 NA0SP= SP=

302H 302HBSC2MSC1 MSC1NA0NA0 BSC2 NA0SP=SP= NA0 SP=312H301H SP= 301H

VLR 312H VLRBSC1

NA0

SP=NA0 311HSP=311H


15/15


SP signaling point

Figure 23 Example network, where BSC2 is moved under MSC2

Moving a BSC under another MSC

1. Prepare the state of the MTP.

To deactivate the signaling route set, use the NVC command.

ZNVC: NA0, 301: , : I NA;

To deny the activation of the signaling route set, use the NVDcommand.

ZNVD: NA0, 301: , : ;

To deactivate signaling links, use the NLC command.

ZNLC: 0&1, I NA;

To deny the activation of signaling links, use the NLD command.

ZNLD: 0&1;

2. Prepare the state of the SCCP.

To deactivate the signaling traffic of the SCCP (into MSC1), use the NGC command.

ZNGC: NA0, 301: I NA: ;

3. Output the results of the MTP and SCCP statistics concerning the old SPC (if nec-

essary).

To stop and result all statistical reports, use the OSDcommand.

ZOSD: REP: ;

4. Execute the exchange of the adjacent signaling point code command.

To change the DPC, use the NRX command.

ZNRX: OWN: NA0, 301: NA0, 302: MSC2: ;

5. Activate the MTP.

To allow the activation of the signaling links, use the NLA command.

ZNLA: 0&1;

To activate the signaling links, use the NLC command.

ZNLC: 0&1, ACT;To allow the activation of a signaling route set, use the NVA command.

ZNVA: NA0, 302: , : ;

To activate the signaling route set, use the NVC command.

ZNVC: NA0, 302: , : ACT;

6. Activate the SCCP.

To activate the SCCP, use the NGC command.

ZNGC: NA0, 302: ACT: ;

7. Restart the BSC.ZUSS: SYM: C=DSK;

8. Verify new network configuration.

To inquire the data of the route set, use the NRI command.

ZNRI : NA0, 302;To inquire the data of the link set, use the NSI command.

ZNSI : NA0, 302;

To inquire the data of the SCCP, use the NGI command.

ZNGI : NA0, 302;

To inquire the data of circuits, use the RCI command.

ZRCI : SEA=6: NET=NA0, SPC=302;

Common Channel Signaling.pdf

Documents

Transcript of Common Channel Signaling.pdf