We use cookies to make our website more user-friendly and to continually improve it. Please agree to the use of cookies in order to proceed with using our websites. More information can be found in our data protection information and our cookie guidelines.

- Required
- Functional
- Personalization
- Required
  These cookies are essential for the operation of the site and enable, for example, security-relevant functions. In addition, we can also use this type of cookie to determine whether you want to remain logged in to your profile in order to make our services available to you more quickly when you visit our website again.
- Functional
  In order to further improve our offer and our website, we collect anonymized data for statistics and analysis. With the help of these cookies we can, for example, determine the number of visitors and the effect of certain pages on our website and optimize our content.
- Personalization
  We use these cookies to make it easier for you to use the site. For example, based on a previous (e.g. product search), you can conveniently access it when you visit our website again.

Attention: Your browser doesn't support javascript or you have deactivated Javascript in your browser. Please enable Javascript in your browser in order to be able to use all functions of this website.

Hydrogen Technologies Standards form the basic framework for market ramp-up
More information
Climate change Standards and specifications support climate targets
More information
Smart Farming Standards and specifications are drivers for the digitalization of agriculture
More information

Standards [CURRENT]

OENORM EN 300356-21 V 4.2.1
Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 21: Anonymous Call Rejection (ACR) supplementary service [ITU-T Recommendation Q.731, clause 4 (1993)]

Edition 2001-11-01

Original language English

Price from 27.20 €

Order from DIN Media

Table of contents

Want to learn more?

Show

Preferred form of address

Male

Female

Neutral

First name*

Last name*

E-mail*

Phone no.

Subject

???din.label.contact.mailSubject???

Message*

Security code*

Here you can find our privacy policy

*Required field

Economic benefits

DIN SPEC

Why do standards cost money?

Get involved in standardization

Terminology

Hydrogen Technologies Standards form the basic framework for market ramp-up

Climate change Standards and specifications support climate targets

Smart Farming Standards and specifications are drivers for the digitalization of agriculture

OENORM EN 300356-21 V 4.2.1 Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 21: Anonymous Call Rejection (ACR) supplementary service [ITU-T Recommendation Q.731, clause 4 (1993)]

Want to learn more?

OENORM EN 300356-21 V 4.2.1
Integrated Services Digital Network (ISDN) - Signalling System No.7 (SS7) - ISDN User Part (ISUP) version 4 for the international interface - Part 21: Anonymous Call Rejection (ACR) supplementary service [ITU-T Recommendation Q.731, clause 4 (1993)]