larger cover

Add To My Wish List

Register your product to gain access to bonus material or receive a coupon.

Signaling System No. 7 (SS7/C7): Protocol, Architecture, and Services

eBook (Watermarked)

  • Sorry, this book is no longer in print.
  • About Watermarked eBooks
  • This PDF will be accessible from your Account page after purchase and requires PDF reading software, such as Acrobat® Reader®.

    The eBook requires no passwords or activation to read. We customize your eBook by discreetly watermarking it with your name, making it uniquely yours.

    Watermarked eBook FAQ

Not for Sale
  • Description
  • Sample Content
  • Updates
  • Copyright 2005
  • Dimensions: 7-3/8" x 9-1/8"
  • Edition: 1st
  • eBook (Watermarked)
  • ISBN-10: 1-58705-357-8
  • ISBN-13: 978-1-58705-357-3

A complete, practical guide to the world's most popular signaling system, including SIGTRAN, GSM-MAP, and Intelligent Networks.

  • Provides in-depth coverage of the SS7 protocols, including implementation details
  • Covers SS7 over IP (SIGTRAN) using real-world examples
  • Covers SS7/C7 from both a North American and European perspective, providing a broad international understanding of the technology and associated standards
  • Explains mobile wireless concepts and signaling, including mobile application part (MAP)
  • Provides a thorough explanation of the Intelligent Network (IN) and associated protocols (INAP/AIN)

Signaling System No. 7 (SS7) is a signaling network and protocol that is used globally to bring telecommunications networks, both fixed-line and cellular, to life. SS7 has numerous applications and is at the very heart of telecommunications. Setting up phone calls, providing cellular roaming and messaging, and supplying converged voice and data services are only a few of the ways that SS7 is used in the communications network. SS7 also provides the point of interconnection between converging voice and data networks. This transition, which affects everyone who works with the data network, has bolstered the need for practical and applied information on SS7. In short, anyone who is interested in telecommunications should have a solid understanding of SS7.

Signaling System No. 7 (SS7/C7): Protocol, Architecture, and Services will help you understand SS7 from several perspectives. It examines the framework and architecture of SS7, as well as how it is used to provide today's telecommunications services. It also examines each level of the SS7 protocol-all the way down to the bit level of messages. In addition, the SIGTRAN standards are discussed in detail, showing the migration from SS7 to IP and explaining how SS7 information is transported over IP.

Table of Contents



1. The Evolution of Signaling.

The History of Signaling.


1976 to Present Day.

Subscriber Signaling.

Address Signals.

Supervisory Signals.

Tones and Announcements.


Network Signaling.

Channel Associated Signaling.

Address Signals.

Limitations of CAS.

Common Channel Signaling (CCS).

Circuit-Related Signaling.

Non-Circuit-Related Signaling.

Common Channel Signaling Modes.


2. Standards.

History of International Telephony Standards.

ITU-T (Formerly CCITT) International Standards.

Regional Standards.


3rd Generation Partnership Project.

3rd Generation Partnership Project 2.

National and Industry Standards.


T1 Committee.

Telcordia (Formerly Bellcore).






3. The Role of SS7.

Signaling System No. 7-Based Services.

Telephone-Marketing Numbers.


Single Directory Number.

Enhanced 911.

Supplementary Services.

Custom Local Area Signaling Services (CLASS).

Calling Name (CNAM).

Line Information Database (LIDB).

Local Number Portability (LNP).

2nd and 3rd Generation Cellular Networks.

Short Message Service (SMS).

Enhanced Messaging Service (EMS).

Private Virtual Networks.

Do-Not-Call Enforcement.

Signaling System No. 7: The Key to Convergence.

Internet Call Waiting and Internet Calling Name Services.

Click-to-Dial Applications.

Web-Browser-Based of Telecommunication Services .

WLAN “Hotspot” Billing.

Location-Based Games.


4. SS7 Network Architecture and Protocols Introduction.

Pre-SS7 Systems.

History of SS7.

SS7 Network Architecture.

Signaling Links and Linksets.

Routes and Routesets.

Node Types.

Link Types.

Signaling Modes.

Signaling Network Structure.

SS7 Protocol Overview.






5. The Public Switched Telephone Network (PSTN).

Network Topology.

PSTN Hierarchy.

PSTN Hierarchy in the United States.

PSTN Hierarchy in the United Kingdom.

Access and Transmission Facilities.



Network Timing.

The Central Office.

Main Distribution Frame.

The Digital Switch.

Switching Matrix.

Call Processing.

Integration of SS7 into the PSTN.

Evolving the PSTN to the Next Generation.



6. Message Transfer Part 2 (MTP2).

Signal Unit Formats.

Fill-In Signal Units.

Link Status Signal Units.

Message Signal Units.

MTP2 Overhead.

Field Descriptions.

Signal Unit Delimitation.

Length Indicator.

Signal Unit Alignment.

Error Detection.

Error Correction.

Basic Error Correction.

Preventive Cyclic Retransmission.

Signaling Link Initial Alignment.

Status Indications.

Signaling Link Error Monitoring.



Processor Outage.

Flow Control.


7. Message Transfer Part 3 (MTP3).

Point Codes.

ITU-T International and National Point Codes.

ANSI National Point Codes.

Message Format.

Service Information Octet.

Signaling Information Field (SIF).

Signaling Message Handling.




Message Load Sharing.

Comparing the IP and MTP3 Protocols.

MTP3 Message Handling Example.

Signaling Network Management.

Network Management Messages (H0/H1 Codes).

Link Management.

Route Management.

Traffic Management.

MTP3/User Part Communication.

Signaling Network Management Example.


8. ISDN User Part (ISUP).

Bearers and Signaling.

ISUP and the SS7 Protocol Stack.

ISUP Standards and Variants

ISUP Message Flow.

Call Setup.

Call Release.

Unsuccessful Call Attempt.

Message Timers.

Circuit Identification Codes.

DPC to CIC Association.

Unidentified Circuit Codes.

Enbloc and Overlap Address Signaling.

Enbloc Signaling.

Overlap Signaling.

Circuit Glare (Dual-Seizure).

Resolving Glare.

Avoiding Glare.

Continuity Test.

Loopback and Transceiver Methods.

Continuity Check Procedure.

ISUP Message Format.

Basic Call Message Formats.

Detailed Call Walk-Through.

Call Setup.

Call Release.

Terminal Portability.

Circuit Suspend and Resume.

ISUP and Local Number Portability.

All Call Query (ACQ).

Query On Release (QOR).

Dropback (Also Known as Release to Pivot).

Onward Routing (OR).

ISUP-ISUP Tandem Calls.

ISUP Message Processing at a Tandem.

Continuity Testing.

Transporting Parameters.

Interworking with ISDN.

End-to-End Signaling.

ISDN Signaling Indicators in the IAM.

Supplementary Services.

Calling Line Identification (CLI) Example.

Call Forwarding Example.

Additional Call Processing Messages.

Maintenance Messages and Procedures.

Circuit Ranges.

Circuit States.

Circuit Validation (ANSI Only).

Continuity Testing.

Blocking and Unblocking Circuits.

Circuit Reset.


9. Signaling Connection Control Part (SCCP).

SCCP Architecture.

SCCP Message Transfer Services.

Connection-oriented Versus Connectionless Services.

User Data and Segmentation.

Connectionless Protocol Classes.

Connection-oriented Protocol Classes.

SCCP Connectionless Control (SCLC).

SCCP Connection-Oriented Control (SCOC).

SCCP Messages and Parameters.

Message Structure.

Message Types.

SCCP Routing Control (SCRC).

Subsystem Number (SSN) Routing.

Global Title Routing.

SCCP Management (SCMG).

Replicate Subsystems.

SCMG Messages.


10. Transaction Capabilities Application Part (TCAP).


Generic Service Interface.

Role of TCAP in Call Control.

TCAP Within the SS7 Protocol Stack.

Transaction and Component Sublayers.

Message Types.


Transaction IDs.

Establishing Transaction IDs.

Releasing Transaction IDs.

Transaction Message Sequence.


Invoke and Return Result Components.

Component IDs.

Operation Codes.


Dialogue Portion.

ITU Dialogue.

ANSI Dialogue.

Message Encoding.

Element Structure.

Element Identifier.

Length Identifier.

Message Layout.

Error Handling.

Protocol Errors.

Application Errors.

End-User Errors.

Handling Application and End-User Errors.

ITU Protocol Message Contents.

Unidirectional Message.

Begin Message.

End Message.

Continue Message.

Abort Message.

ANSI Protocol Message Contents.

Unidirectional Message.

Query With/Without Permission.

Conversation With/Without Permission.

Response Message.

Protocol Abort (P-Abort) Message.

User Abort (U-Abort) Message.

ANSI National Operations.

ANSI Parameters.



11. Intelligent Networks (IN).

The Intelligent Network.

Service Logic and Data.

Service Logic.

Service Data.

Service Distribution and Centralization.

IN Services.

IN and the SS7 Protocol.

Evolution of the Network.


Initial Services.

IN/1 Toll-Free (E800) Example.

The Advanced Intelligent Network (AIN 0.X, IN CS-X).

Basic Call State Models (BCSM).

Network Architecture.

ITU Intelligent Network Conceptual Model (INCM).

AIN 0.

IN CS-1/AIN 0.1.

IN CS-2/AIN 0.2.

AIN 0.2 Call Control Messages from the SCP.

AIN 0.2 Time Of Day (TOD) Routing Example.

Additional IN Service Examples.

Intelligent Network Application Protocol (INAP).

Basic Toll-Free Example Using INAP.

Service Creation Environment (SCE).


12. Cellular Networks.

Network Architecture.

Mobile Station (MS).

Subscriber Identity Module (SIM).

Base Transceiver Station (BTS).

Base Station Controller (BSC).

Mobile Switching Centre (MSC).

Home Location Register (HLR).

Visitor Location Register (VLR).

Equipment Identity Register (EIR).

Authentication Center (AuC).

Serving GPRS Support Node (SGSN).

Gateway GPRS Support Node (GGSN).

Interfaces and Protocols.


Mobile Application Part (MAP).

Mobility Management and Call Processing.

Location Update.

Mobile Terminated Call (MTC).


13. GSM and ANSI-41 Mobile Application Part (MAP).

MAP Operations.

Mobility Management.

Location Management.


Authentication Management.

IMEI Management.

Subscriber Management.

Fault Recovery.

Operation and Maintenance.

Subscriber Tracing.


Call Handling.

Supplementary Services.

Unstructured Supplementary Services (USSs).


Short Message Service (SMS).







14. SS7 in the Converged World.

Next Generation Architecture.


Stream Control Transmission Protocol (SCTP).

User Adaptation (UA) Layers.

UA Common Terminology.

Routing Keys and Interface Identifiers.

MTP Level 3 UA (M3UA).

Messages and Formats.

ASPSM and ASPTM Messages.

SS7/C7 Variant Specifics.

Message Flow Example.

SCCP User Adaptation (SUA).

Messages and Formats.

Message Flow Example.

MTP Level 2 User Adaptation (M2UA).

Messages and Formats.

MTP Level 2 Peer Adaptation (M2PA).

ISDN User Adaptation (IUA).

Transport Adaptation Layer Interface (TALI).

Early Cisco SS7/IP Solution.

SS7 and SIP/H.323 Interworking.



15. SS7 Security and Monitoring.

Traffic Screening.

Screening Considerations.

MTP3: Management Messages.

Originating Point Code.

Destination Point Code.


SCCP User Messages.

Management Messages.


Traffic Monitoring.

Q.752 Monitoring Measurements.


16. SS7 Testing.

Test Equipment.

Test Specification Creation.

MTP 2 Testing.

Test Configuration.

Example 1: Initialization (Power-up), Test 1.1.

Example 2: Normal Alignment—Correct Procedure (FISU), Test 1.5.

Example 3: Individual End Sets Emergency, Test 1.22.

Example 4: SIO Received During Link In-Service, Test 1.28.

Example 5: Unexpected Signal Units/Orders in “In-Service” State, Test 2.7.

Example 6: Link Aligned Ready (Break Tx Path), Test 3.1.

Example 7: Link Aligned Ready (Corrupt FIBs—Basic), Test 3.2.

Example 8: Set and Clear LPO While Link In-Service, Test 4.1.

Example 9: SU Delimitation, Alignment, Error Detection, and Correction, Test 5.1.

Example 10: Error Rate of 1 in 256—Link Remains In-Service, Test 6.1.

Example 11, Test 7.1.

Example 12: Check RTB Full, Test 8.3.

Example 13: Forced Retransmission with the Value N1, Test 9.3.

Example 14: Congestion Abatement, Test 10.1.

MTP 3 Testing.

Test Configuration.

Example 1: First Signaling Link Activation, Test 1.1.

Example 2: Load Sharing within a Linkset (All Links Available), Test 2.4.1.

Example 3: Inaccessible Destination—Due to a Linkset Failure, Test 2.6.1.

ISUP Testing.

Test Configuration.

Example 1: CCR Received—Successful, Test 1.4.1.

Example 2: Overlap Operation (with SAM), Test 2.2.2.

Example 3: Timers T1 and T5—Failure to Receive a RLC, Test 5.2.3.

ISUP Supplementary Services Testing.

Test Configuration.

Example 1: CUG Call with Outgoing Access Allowed and Sent, Test 2.1.1.

Example 2: CLIP—Network Provided and Sent, Test 3.1.1.

Example 2: COL—Requested and Sent, Test 6.1.1.

SCCP Testing.

Test Configuration.

Example 1: Local DPC and SSN Included, DPC and SSN Available, GT and SSN Included and Sent, Test

Example 2: Remote DPC and SSN Included, DPC and/or SSN Unavailable— Return Option Not Set, Test

Example 3: Local DPC and SSN, and SSN Available GT Not Included, SSN Included, Test

TCAP Testing.

Test Configuration.

Example 1: Clearing Before Subsequent Message; Valid Clearing from Initiating Side; Prearranged Ending, Test (1).

Example 2: First Continue Message; OTID Absent, Test (1).

Example 3: Inopportune Reject Component, Test (1).



Appendix A: MTP Messages (ANSI/ETSI/ITU).

Appendix B: ISUP Messages (ANSI/UK/ETSI/ITU-T).

Appendix C: SCCP Messages (ANSI/ETSI/ITU-T).

Appendix D: TCAP Messages and Components.

Appendix E: ITU-T Q.931 Messages.

Appendix F: GSM and ANSI MAP Operations.

Appendix G: MTP Timers in ITU-T/ETSI/ANSI Applications.

Appendix H: ISUP Timers for ANSI/ETSI/ITU-T Applications.

Appendix I: GSM Mobile Country Codes (MCC) and Mobile Network Codes (MNC).

Appendix J: ITU and ANSI Protocol Comparison.

Appendix K: SS7 Standards.

Appendix L: Tektronix Supporting Traffic.

Appendix M: Cause Values.




Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Cisco Press products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by Cisco Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive:

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020