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ISUP Hop Counter and SIP Max Forwards Mapping

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Support of ISUP Hop Counter and SIP Max-Forwards Mapping

Table Of Contents

Support of ISUP Hop Counter and SIP Max-Forwards Mapping

Feature Overview

Benefits

Related Documents

Supported Standards, MIBs, and RFCs

Prerequisites for Using This Feature

Provisioning Tasks

Provisioning Prerequisites

Collecting Device Data

Collecting Signal Path Data

Provisioning Procedures

Provisioning Basics

Adding Components

Adding Properties

Modifying ISUP to SIP and SIP to ISUP Ratio Properties

Deleting ISUP to SIP and SIP to ISUP Ratio Properties

Provisioning Examples

Command Reference

Modified MML Commands

PROV-ADD:sigsvcprop—Provision Signaling Service Properties
(Release 9.6(1))

Reference Information

Properties

Obtaining Documentation

Cisco.com

Product Documentation DVD

Ordering Documentation

Documentation Feedback

Cisco Product Security Overview

Reporting Security Problems in Cisco Products

Obtaining Technical Assistance

Cisco Technical Support & Documentation Website

Submitting a Service Request

Definitions of Service Request Severity

Obtaining Additional Publications and Information

Glossary


Support of ISUP Hop Counter and SIP Max-Forwards Mapping


Document Release History

Publication Date
Comments

February 20, 2006

Initial version of the document.


Feature History

Release
Modification

9.6(1)

This feature was introduced on the PGW 2200 in software Release 9.6(1).


This document describes the Support of ISUP Hop Counter and SIP Max-Forwards Mapping feature.

This feature is described in the following sections:

Feature Overview

Supported Standards, MIBs, and RFCs

Prerequisites for Using This Feature

Provisioning Tasks

Provisioning Examples

Command Reference

Reference Information

Obtaining Documentation

Documentation Feedback

Cisco Product Security Overview

Obtaining Technical Assistance

Obtaining Additional Publications and Information

Glossary

Feature Overview

The Support of ISUP Hop Counter and SIP Max-Forwards Mapping feature supports mapping of the ISDN User Part (ISUP) hop counter parameter and the Session Initiation Protocol (SIP) Max-Forwards field to prevent loops when calls are made between the public switched telephone network (PSTN) and SIP domains on the Cisco PGW 2200.

This feature provides the following:

Applies mapping between the SIP Max-Forwards and the ISUP hop counter

Supports both ITU and ANSI ISUP hop counter and SIP Max-Forwards

Supports mapping between SIP-to-ISUP and SIP-to-EISUP

Adds two sigPath property values: SipToIsupRatio, for mapping from SIP to ISUP or EISUP and IsupToSipRatio, for mapping from ISUP or EISUP to SIP

Benefits

Prevent Loops for Calls Between PSTN and SIP Domains

For a call between ISUP or EISUP and SIP, the setting of the SipToIsupRatio and IsupToSipRatio properties in the MGC allows mapping to the hop counter field in the Initial Address Message (IAM) and Max-Forwards field in the INVITE request message. This feature adds the mapping function between the two fields into the MGC. The mapping is only applied between SIP and ISUP (both ITU and ANSI), and SIP and EISUP. This feature is applicable to ANSI ISUP and ITU ISUP (Q.761),

Related Documents

This document contains information that is related strictly to this feature. The documents that contain additional information related to the Cisco Media Gateway Controller (MGC) are listed below:

Release Notes for Cisco Media Gateway Controller Software Release 9.6(1)

Cisco Media Gateway Controller Hardware Installation Guide

Regulatory Compliance and Safety Information for the Cisco Media Gateway Controller

Cisco Media Gateway Controller Software Release 9 Installation and Configuration Guide

Cisco Media Gateway Controller Software Release 9 Provisioning Guide

Cisco Media Gateway Controller Software Release 9 Dial Plan Guide

Cisco Media Gateway Controller Software Release 9 MML Command Reference

Cisco Media Gateway Controller Software Release 9 Messages Reference Guide

Cisco Media Gateway Controller Software Release 9 Billing Interface Guide

Cisco Media Gateway Controller Software Release 9 Management Information Base Guide

Cisco Media Gateway Controller Software Release 9 Operations, Maintenance, and Troubleshooting Guide

Supported Standards, MIBs, and RFCs

Standards

No new or modified standards are supported by this feature.

MIBs

No new or modified MIBs are supported by this feature.

For more information on the MIBs used in the Cisco MGC software, refer to the Cisco Media Gateway Controller Software Release 9 Management Information Base Guide.

RFCs

No new or modified RFCs are supported by this feature.

Prerequisites for Using This Feature

You must have Cisco MGC software Release 9.6(1). Prerequisites for this release can be found in the Release Notes for the Cisco Media Gateway Controller Software Release 9.6(1).

Provisioning Tasks

The following sections describe the provisioning tasks related to this feature:

Provisioning Prerequisites

Provisioning Procedures

Provisioning Prerequisites

This section lists the data that you must gather to successfully provision this feature. For more information on planning the provisioning for the rest of the Cisco MGC software, refer to the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

Collecting Device Data

The devices to which the MGC communicates must be provisioned. You must be ready to enter the following data about the external devices:

MML name

Component description

The type of the external node

ISDN signaling type

You can define the parameters for your external nodes in Table 2 in the "Properties" section.

Collecting Signal Path Data

The signal path component types represent the signaling service to particular Cisco media gateways, or other devices to which the MGC is connected. You must be ready to enter the following signal path data:

MML name

Component description

MML name of the associated external node

Customer group ID

Signaling port number (physical port on the Cisco media gateway)

Signaling port slot (physical slot on the Cisco media gateway)

You can define the parameters for your NAS signaling services in Table 2 in the "Properties" section.

Provisioning Procedures

Provision the transport path between the IUA IOCCs of the Cisco MGC 2200 and the external Cisco media gateway nodes. Communication between the Cisco MGC 2200 and the Cisco media gateways is provisioned so that there is a reliable communication path between the two platforms.

This provisioning is performed when an external node is modified to use an SCTP-based protocol or when a new external node is added to the Cisco MGC 2200. This section covers the following provisioning topics:

Provisioning Basics

Adding Properties

Modifying ISUP to SIP and SIP to ISUP Ratio Properties

Deleting ISUP to SIP and SIP to ISUP Ratio Properties

Provisioning Basics

Use the procedures in this section to start a provisioning session and save and activate the changes you have made.

Starting a Provisioning Session

Saving and Activating Your Provisioning Changes

Ending a Provisioning Session Without Activating Your Changes

Retrieving Provisioning Data

For more detailed information about provisioning your Cisco MGC, refer to the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

Starting a Provisioning Session

You may need to start a provisioning session as part of your system operations. To do this, log in to the active Cisco MGC, start an MML session, and enter the following command:

prov-sta::srcver="curr_ver",dstver="mod_ver"

Where:

curr_ver—The name of the current configuration version. In place of the name of the current configuration version, you can also enter:

new—A new default session configuration; no existing source configuration is available.

active—Selects the active configuration as the source for configuration changes.


Note If you do not know the name of your current configuration session, you can learn it by using the procedure described in the "Retrieving Data on the Current Provisioning Session" section on page 7.


mod_ver—A new configuration version name that contains your provisioning changes.

For example, to use a configuration version called ver1 as the basis for a version to be called ver2, you would enter the following command:

prov-sta::srcver="ver1",dstver="ver2"

Once a provisioning session is underway, you can use the prov-add, prov-ed, and prov-dlt MML commands to add, modify, and delete components on your system. This document describes how to provision this feature. For more information on provisioning other components on your Cisco MGC, refer to the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

There are two ways to close your provisioning session: saving and activating your provisioning changes, as described in the "Saving and Activating Your Provisioning Changes" section or ending your provisioning session without saving and activating your changes, as described in the "Ending a Provisioning Session Without Activating Your Changes" section.

Saving and Activating Your Provisioning Changes

When you have completed making provisioning changes in your session, you must enter a command to save and activate your changes. There are two different provisioning MML commands that do this: prov-cpy and prov-dply.


Caution Using the prov-cpy and prov-dply MML commands can severely impact your system's call processing performance, depending on the extent of your provisioning changes. We recommend that these commands be issued during a maintenance window when traffic is minimal.

The prov-cpy MML command is used to save and activate your changes on simplex Cisco MGC (single-host) systems.


Note When you enter the prov-cpy command, your provisioning session is also automatically ended. If you want to make additional provisioning changes, you must start a new provisioning session as described in the "Starting a Provisioning Session" section.



Caution Do not use the prov-cpy command to save and activate your changes on a continuous-service Cisco MGC system (one with active and standby hosts) system. Saving and activating using prov-cpy on such a system would require using the prov-sync MML command to synchronize the provisioning data on the active and standby hosts. The system does not indicate when the synchronization process fails, which would create problems when a switchover operation occurs.

The prov-dply MML command is used to save and activate your changes on the active and standby
Cisco MGCs in a continuous-service system. This command should not be used on a Cisco MGC in a simplex configuration.


Note When you enter the prov-dply command, your provisioning session is also automatically ended, unless an error occurs during execution. If you want to make additional provisioning changes, you must start a new provisioning session, as described in the "Starting a Provisioning Session" section.


Ending a Provisioning Session Without Activating Your Changes

If you want to end a provisioning session without saving and activating the changes you have entered, enter the prov-stp MML command. This command ends your current provisioning session, and your changes are not entered.

Retrieving Provisioning Data

You can use the prov-rtrv MML command to retrieve information about your current provisioning settings. The ways you can use this command to retrieve provisioning data are described in the following sections:

Retrieving Data for an Individual Component

Retrieving Data for All Components

Retrieving Data for All Components of a Particular Type

Retrieving Data on the Current Provisioning Session

Retrieving Data on Supported Signaling Protocols

Retrieving Data for an Individual Component

You can retrieve provisioning data on any individual component on your system. To do this, log in to the active Cisco MGC, start an MML session, and enter the following command:

prov-rtrv:component:name=MML_name

Where:

component—The MML component type associated with the desired component. You can find a complete list of MML component types in the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

MML_name—The MML name for the desired component. You can determine the MML names for the various components using the prov-rtrv:all MML command.

For example, to view the provisioning data for an SS7 signaling service called ss7svc1, you would enter the following command:

prov-rtrv:ss7path:name="ss7svc1"

The response to the command is dependent upon the component type associated with the desired component. For example, to view the properties for an SUA routing key called suakey1, you would enter the following command:

prov-rtrv:suakey:name="suakey1"

Retrieving Data for All Components

You can retrieve data on all of the components provisioned on your system. To do this, log in to the active Cisco MGC, start an MML session, and enter the following command:

prov-rtrv:all

Retrieving Data for All Components of a Particular Type

You can retrieve provisioning data on all components of a particular type on your system. To do this, log in to the active Cisco MGC, start an MML session, and enter the following command:

prov-rtrv:component:"all"

Where component is the MML component type associated with the desired component group. You can find a complete list of MML component types in the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

For example, to view the provisioning data for all SS7 signaling services, you would enter the following command:

prov-rtrv:ss7path:"all"

Retrieving Data on the Current Provisioning Session

You can retrieve provisioning data on the current provisioning session. To do this, log in to the active Cisco MGC, start an MML session, and enter the following command:

prov-rtrv:session

The system returns a response similar to the following:

MGC-02 - Media Gateway Controller 2004-01-13 13:39:19
M  RTRV
   "session=jtest:session"
   /*
Session ID = mml1
SRCVER = active
DSTVER = jtest
   */

Retrieving Data on Supported Signaling Protocols

You can retrieve protocol data for the current provisioning session. To do this, log in to the active Cisco MGC, start an MML session, and enter the following command:

prov-rtrv:variants 

Adding Components

The range of the SipToIsupRatio and IsupToSipRatio property values is 1 - 4 and the default value of each property is 0.

When the two property values are 0, no mapping is required, and the existing mechanism is applied.

The mapping for each direction is independent of mapping for the other. When either property value is set to 0, there is no mapping for the corresponding direction.

When both property values are not 0, the mapping mechanism is applied two both directions.

When you are mapping from SIP-to-ISUP or from SIP-to-EISUP, the Hop Counter value is derived from Max-Forwards ³ SipToIsupRatio; it is then decremented by 1 before being sent out to the ISUP or EISUP trunk group(s).

When you are mapping from ISUP-to-SIP or EISUP-to-SIP, the Max-Forwards value is derived from IsupToSipRatio x Hop Counter; and then decremented by 1 before being sent to the SIP outgoing trunk group(s).

When you are mapping from SIP or Generic Transparency Descriptor (GTD) to ISUP, the Hop Counter value in GTD takes precedence over the SIP Max-Forwards value when the Hop Counter is present; the Max-Forwards value is used to derive the ISUP Hop Counter.

When the derived Max-Forwards or Hop Counter value is not integer, rounding is applied. Values from 0.5 through 0.9 are rounded up to 1, and values from 0.4 through 0.1 are rounded down to 0.

When decrementing the derived value of Max-Forwards or Hop Counter by 1 results in 0, the call is released.

For a call between ISUP or EISUP and SIP, this feature adds the Hop Counter field in the Initial Address Message (IAM) and the Max-Forwards field in the INVITE request message mapping function between the two fields into the MGC. For a SIP-to-ISUP call, in the incoming side, the SIP OCC first checks the received Max-Forwards value, rounds it up or down, and then stores the result value. In the outgoing side, the ISUP TCC retrieves the Max-Forwards value and decreases it by 1. If the result is greater than 0, the call continues. However, if the result value is less than 0, the call is released.

For an ISUP-to-SIP call, in the incoming side, the ISUP OCC first checks the received Hop Counter field in the IAM and stores that value in the outgoing side. The SIP TCC retrieves the value, rounds the value up or down, then decreases the result value by 1. If the final result is greater than 0, that value is assigned to Max-Forwards and the call continues. However, if the result value is less than 0, the call is released.

This feature is applicable to ANSI ISUP and ITU ISUP (Q.761), but it is not applicable to ITU ISUP (Q.767) because the Hop Counter field does not exist in any messages that comply with Q.767.

The following sections show examples of mapping from SIP to ISUP or EISUP.

Mapping from SIP to ISUP or EISUP

The SIP originating Max-Forwards value = 50

The SipToIsupRatio property value = 3

The resulting Hop Counter value = 50 ³ 3 = 17 - 1 = 16


Note For 50 ³ 3 = 16.67. the quotient remainder of 0.67 is rounded up to 1, therefore, 17 - 1 is the derived Hop Counter value.


Mapping from ISUP or EISUP to SIP

The ISUP originating Hop Counter Value = 22

The IsupToSipRatio property value = 2

The resulting Max-Forwards value = 22 x 2 - 1 = 43

Calls released when resulting mapping of either value is 0

The SIP originating Max-Forwards value = 5

The SipToIsupRatio property value = 4

The resulting Hop Counter value = 1 (the actual quotient was 0.25, which is rounded down to 0) - 1 = 0

Mapping SIP or GTD to ISUP when GTD Hop Counter is Present

The SIP originating Max-Forwards value = 50

The GTD Hop Counter value = 5

The resulting ISUP Hop Counter value = 4 (GTD Hop Counter decremented by 1)

Mapping SIP or GTD to ISUP when GTD Hop Counter is Absent

The SIP originating Max-Forwards value = 50

The SipToIsupRatio property value = 3

The resulting Hop Counter value = 50 ³ 3 = 17 - 1 = 16 (the actual quotient was 16.67, which is rounded up to 17)

Adding Properties

This section contains the procedures that you perform to add the SipToIsupRatio and IsupToSipRatio properties to your Cisco MGC provisioning data.

Adding the SIP to ISUP Ratio

Adding the ISUP to SIP Ratio

Adding the SIP to ISUP Ratio

To add the SIP to ISUP ratio property in your provisioning data, perform the following steps:


Step 1 Start a provisioning session, as described in the "Starting a Provisioning Session" section.

Step 2 Provision the SipToIsupRatio property with the following MML command.

mml> prov-add:sigsvcprop:name="sip-path",SipToIsupRatio="1" 

Step 3 Check the SipToIsupRatio value with the following MML command:

mml> prov-rtrv:sigsvcprop:name="sip-sigpath" 

Verify that the SipToIsupRatio property value is 1.


Where:

name—The name you want to give to the signaling service property. The name can be as many as 20 characters long and can contain numbers, letters, and the dash (-) symbol. The name should begin with a letter.

Step 4 If there are no other parameters or components that you need to provision, end your provisioning session as described in the "Saving and Activating Your Provisioning Changes" section.


Adding the ISUP to SIP Ratio

To add the ISUP to SIP ratio to your provisioning data, perform the following steps:


Step 1 Start a provisioning session, as described in the "Starting a Provisioning Session" section.

Step 2 Provision the IsupToSipRatio property with the following MML command.

mml> prov-add:sigsvcprop:name="sip-path",isupToSipRatio="1" 

Step 3 Check the IsupToSipRatio value with the following MML command:

mml> prov-rtrv:sigsvcprop:name="sip-sigpath" 

Verify that the IsupToSipRatio property value is 1.


Where:

name—The name you want to give to the signaling service property. The name can be as many as 20 characters long and can contain numbers, letters, and the dash (-) symbol. The name should begin with a letter.

Step 4 If there are no other parameters or components that you need to provision, end your provisioning session as described in the "Saving and Activating Your Provisioning Changes" section.


Modifying ISUP to SIP and SIP to ISUP Ratio Properties

The following sections contain the procedures for modifying the ISUP to SIP and SIP to ISUP ratio properties in your Cisco MGC provisioning data:

Modifying ISUP to SIP and SIP to ISUP Ratios

Modifying ISUP to SIP and SIP to ISUP Ratios

To modify the ISUP to SIP and SIP to ISUP ratios of a Cisco media gateway external node, perform the following steps:


Step 1 Start a provisioning session as described in the "Starting a Provisioning Session" section.

Step 2 Modify the SipToIsupRatio and IsupToSipRatio values with the following MML command.

mml> prov-ed:sigsvcprop:name="sip-path",SipToIsupRatio="1",IsupToSipRatio="2" 

Where:

name—The name of the signaling service property to be modified.

Step 3 If there are no other parameters or components that you need to modify, end your provisioning session as described in the "Saving and Activating Your Provisioning Changes" section.


Deleting ISUP to SIP and SIP to ISUP Ratio Properties

The following sections contain the procedures for deleting the ISUP to SIP and SIP to ISUP ratio properties in your Cisco MGC 2200 provisioning data:

Deleting the ISUP to SIP Ratio

Deleting the SIP to ISUP Ratio

Deleting the ISUP to SIP Ratio


Step 1 Start a provisioning session, as described in the "Starting a Provisioning Session" section.

Step 2 Delete the ISUP to SIP ratio with the following MML command.

mml> prov-dlt:sigsvcprop:name="sip-path",IsupToSipRatio 

Step 3 After deleting the IsupToSipRatio property on sip-path, check the IsupToSipRatio property value and verify that it is the default value of 0.

Step 4 If there are no other parameters or components that you need to provision, end your provisioning session as described in the "Saving and Activating Your Provisioning Changes" section.


Deleting the SIP to ISUP Ratio


Step 1 Start a provisioning session, as described in the "Starting a Provisioning Session" section.

Step 2 Delete the SIP to ISUP ratio with the following MML command.

mml> prov-dlt:sigsvcprop:name="sip-path",SipToIsupRatio 

Step 3 After deleting the SipToIsupRatio property on sip-path, check the SipToIsupRatio property value and verify that it is the default value of 0.

Step 4 If there are no other parameters or components that you need to provision, end your provisioning session as described in the "Saving and Activating Your Provisioning Changes" section.


Provisioning Examples

This section provides a provisioning example for this feature. Additional provisioning examples for the Cisco MGC software can be found in the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.


prov-add:sigsvcprop:name="sip-path",SipToIsupRatio="1" 
prov-add:sigsvcprop:name="sip-path",IsupToSipRatio="1" 

Command Reference

This section documents new, modified, or deleted Man-Machine Language (MML) commands. All other MML commands are documented in the Cisco Media Gateway Controller Software Release 9 MML Command Reference Guide.

Modified MML Commands

This section contains the MML commands that are modified for this feature.

PROV-ADD:sigsvcprop—Provision Signaling Service Properties
(Release 9.6(1))

Purpose:

This MML command provisions signaling service properties.

Syntax:

prov-add:sigsvcprop:name="name",SipToIsupRatio="value" 
prov-add:sigsvcprop:name="name",IsupToSipRatio="value" 

Input Description:

Name—Name of an existing signalling service. Enter an alphanumeric string up to 20 characters in length.

SipToIsupRatio—The SIP to ISUP ratio property.
or

IsupToSipRatio—The ISUP to SIP ratio property

value—Valid values are:

0—The mapping is disabled

1 through 4—The mapping ratio value.

Example:

The MML command shown in the following example sets the SIP to ISUP ratio to 1 and the ISUP to SIP ratio 2:

mml> prov-ed:sigsvcprop:name="sip-path",SipToIsupRatio="1", 
IsupToSipRatio="2" 

Comments:

Performance Impact Category: A


Reference Information

The following sections contain reference material related to this feature. Information is included on the following areas:

Properties

Properties

The properties in this section are used for this feature. For information on other properties for the Cisco MGC software, refer to the Cisco Media Gateway Controller Software Release 9 Provisioning Guide.

The parent object for the properties involved in this feature are found in Table 1.

Table 1 Software Properties Related to This Feature

Property Name
Parent Object
 
AVM
DPNSS
EISUP
IOCC
ISDNPRI
MGCP
RLM
SESSION
SGCP
SS7-ANSI
SS7-China
SS7-ITU
SS7-Japan
SS7-UK
TALI-IOCC
TCAPOverIP
TrunkGroup
VSI
SIP

SipToIsupRatio

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

X

IsupToSipRatio

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

X


The properties used for this feature are described in Table 2 and their dynamically provisionable status is listed in Table 3.

Table 2 Properties Added with This Feature 

Property
Definition

SipToIsupRatio

Set the ratio of Max_Forwards to Hop Counter for a call from SIP to ISUP. Valid range: 0 or 1 through 4. (0 indicates the mapping does not function).

Valid values: 0 through 4.

Default value: 0

IsupToSipRatio

Set the ratio of Max_Forwards to Hop Counter for a call from ISUP to SIP. Valid range: 0 or 1 through 4. (0 indicates the mapping does not function).

Valid values: 0 through 4.

Default value: 0


Table 3 Provisionable Properties 

Property
Modified Value Takes Effect Without Restart

SipToIsupRatio

Yes

IsupToSipRatio

Yes


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The Cisco Technical Support & Documentation website provides online documents and tools for troubleshooting and resolving technical issues with Cisco products and technologies. The website is available 24 hours a day, at this URL:

http://www.cisco.com/techsupport

Access to all tools on the Cisco Technical Support & Documentation website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register at this URL:

http://tools.cisco.com/RPF/register/register.do


Note Use the Cisco Product Identification (CPI) tool to locate your product serial number before submitting a web or phone request for service. You can access the CPI tool from the Cisco Technical Support & Documentation website by clicking the Tools & Resources link under Documentation & Tools. Choose Cisco Product Identification Tool from the Alphabetical Index drop-down list, or click the Cisco Product Identification Tool link under Alerts & RMAs. The CPI tool offers three search options: by product ID or model name; by tree view; or for certain products, by copying and pasting show command output. Search results show an illustration of your product with the serial number label location highlighted. Locate the serial number label on your product and record the information before placing a service call.


Submitting a Service Request

Using the online TAC Service Request Tool is the fastest way to open S3 and S4 service requests. (S3 and S4 service requests are those in which your network is minimally impaired or for which you require product information.) After you describe your situation, the TAC Service Request Tool provides recommended solutions. If your issue is not resolved using the recommended resources, your service request is assigned to a Cisco engineer. The TAC Service Request Tool is located at this URL:

http://www.cisco.com/techsupport/servicerequest

For S1 or S2 service requests or if you do not have Internet access, contact the Cisco TAC by telephone. (S1 or S2 service requests are those in which your production network is down or severely degraded.) Cisco engineers are assigned immediately to S1 and S2 service requests to help keep your business operations running smoothly.

To open a service request by telephone, use one of the following numbers:

Asia-Pacific: +61 2 8446 7411 (Australia: 1 800 805 227)
EMEA: +32 2 704 55 55
USA: 1 800 553-2447

For a complete list of Cisco TAC contacts, go to this URL:

http://www.cisco.com/techsupport/contacts

Definitions of Service Request Severity

To ensure that all service requests are reported in a standard format, Cisco has established severity definitions.

Severity 1 (S1)—Your network is "down," or there is a critical impact to your business operations. You and Cisco will commit all necessary resources around the clock to resolve the situation.

Severity 2 (S2)—Operation of an existing network is severely degraded, or significant aspects of your business operation are negatively affected by inadequate performance of Cisco products. You and Cisco will commit full-time resources during normal business hours to resolve the situation.

Severity 3 (S3)—Operational performance of your network is impaired, but most business operations remain functional. You and Cisco will commit resources during normal business hours to restore service to satisfactory levels.

Severity 4 (S4)—You require information or assistance with Cisco product capabilities, installation, or configuration. There is little or no effect on your business operations.

Obtaining Additional Publications and Information

Information about Cisco products, technologies, and network solutions is available from various online and printed sources.

Cisco Marketplace provides a variety of Cisco books, reference guides, documentation, and logo merchandise. Visit Cisco Marketplace, the company store, at this URL:

http://www.cisco.com/go/marketplace/

Cisco Press publishes a wide range of general networking, training and certification titles. Both new and experienced users will benefit from these publications. For current Cisco Press titles and other information, go to Cisco Press at this URL:

http://www.ciscopress.com

Packet magazine is the Cisco Systems technical user magazine for maximizing Internet and networking investments. Each quarter, Packet delivers coverage of the latest industry trends, technology breakthroughs, and Cisco products and solutions, as well as network deployment and troubleshooting tips, configuration examples, customer case studies, certification and training information, and links to scores of in-depth online resources. You can access Packet magazine at this URL:

http://www.cisco.com/packet

iQ Magazine is the quarterly publication from Cisco Systems designed to help growing companies learn how they can use technology to increase revenue, streamline their business, and expand services. The publication identifies the challenges facing these companies and the technologies to help solve them, using real-world case studies and business strategies to help readers make sound technology investment decisions. You can access iQ Magazine at this URL:

http://www.cisco.com/go/iqmagazine

or view the digital edition at this URL:

http://ciscoiq.texterity.com/ciscoiq/sample/

Internet Protocol Journal is a quarterly journal published by Cisco Systems for engineering professionals involved in designing, developing, and operating public and private internets and intranets. You can access the Internet Protocol Journal at this URL:

http://www.cisco.com/ipj

Networking products offered by Cisco Systems, as well as customer support services, can be obtained at this URL:

http://www.cisco.com/en/US/products/index.html

Networking Professionals Connection is an interactive website for networking professionals to share questions, suggestions, and information about networking products and technologies with Cisco experts and other networking professionals. Join a discussion at this URL:

http://www.cisco.com/discuss/networking

World-class networking training is available from Cisco. You can view current offerings at this URL:

http://www.cisco.com/en/US/learning/index.html

Glossary

Table 4 contains expansions of acronyms and technical terms used in this feature module.

Table 4 Acronyms and Expansions

Acronym
Expansion

GTD

Generic Transparency Descriptor

HOC

Hop Counter, in GTD format

IAM

Initial Address Message

ISDN

Integrated Services Digital Network

ISUP

ISDN User Part

MGC

(Cisco) Media Gateway Controller

PGW

PSTN Gateway

PSTN

public switched telephone network

SC

Signaling Controller

SIP

Session Initiation Protocol

VSC

Virtual Switch Controller