Skip to end of metadata
Go to start of metadata

Download PDF Document



2019-08-29
All Mediatrix units
45.0.1809
Top

1 Secure Real-Time Transport Protocol

Secure Real-time Transport Protocol (SRTP) is a profile of Real-time Transport Protocol (RTP) that provides encryption, message authentication, and replay attack protection.

SRTP can be enabled on all Mediatrix unit endpoints, or on one or more specific endpoints. However, SRTP encryption and authentication requires more processing therefore, if SRTP is enabled, the number of calls that the Mediatrix unit can handle simultaneously may be reduced, depending of the enabled codecs . (For more details on resources limitations with SRTP and conferences, refer to the DGW Configuration Guide - Limitations of DGW Platforms document published on the Media5 documentation portal at https://documentation.media5corp.com/ ).

To reduce the impact on the number of simultaneous calls a Mediatrix unit can handle, is it possible to disable all voice or data codec, including the T.38 protocol, and keep only the G.711 voice codec enabled.

Important

If Secure RTP (SRTP) is enabled on at least one line, it is acceptable to have the secure SIP transport (TLS) disabled for testing purposes. However, this configuration must never be used in a production environment, since an attacker could easily break it. Enabling TLS for SIP Transport is strongly recommended and is usually mandatory for security interoperability with third-party equipments.

The Mediatrix unit supports the MIKEY protocol using pre-shared keys (MIKEY-PS as per RFC 3830) or the SDES protocol for negotiating SRTP keys

Top

2 Basic Tasks

Top

2.1 Enabling Secure Media (SRTP) on All endpoints of a Mediatrix Unit

Before You Start
Encrypted/secure signaling must be configured.
Steps
  1. Go to Media /Security .
  2. From the Select Endpoint selection list, choose Default .
  3. In the Security table, Mode drop box, select Secure or Secure with fallback .
  4. From the Key Management Protocol drop box, select the protocol.

    Note

    Enabling SDES instead of MIKEY will make the INVITE slightly different. SDES parameters will be added to the SDP Media Attributes instead of the Session Attributes.

  5. From the Key Management Protocol drop box, select the encryption algorithm.

    Important

    Choosing Null (debug only) will not encrypt the RTP. This option should only be selected for debugging purposes.

  6. From the Allow Unsecure T.38 with Secure RTP selection, choose if unsecure T.38 is allowed with RTP.

    Note

    To avoid an impact on the number of simultaneous calls a Mediatrix unit can handle in SRTP, set the Allow Unsecure T.38 with Secure RTP parameter to No .

  7. Click Apply .
Result
All new SIP exchanges will contain RTP/SAVP negotiation elements.
Top

2.2 Enabling Secure Media (SRTP) on a Specific Endpoint

Before You Start
Encrypted/secure signaling must be configured.
Steps
  1. Go to Media /Security .
  2. From the Select Endpoint selection list, choose an endpoint.

    Note

    The list of available endpoints will vary depending on the type of unit being used.

  3. In the Security table, from the Mode drop box, select Secure or Secure with fallback .
  4. From the Key Management Protocol drop box, select the protocol.

    Note

    Enabling SDES instead of MIKEY will make the INVITE slightly different. SDES parameters will be added to the SDP Media Attributes instead of the Session Attributes.

  5. From the Key Management Protocol drop box, select the encryption algorithm.

    Important

    Choosing Null (debug only) will not encrypt the RTP. This option should only be selected for debugging purposes.

  6. Click Apply .
Result
All new SIP exchanges going through the specified endpoint will contain RTP/SAVP negotiation elements.
Top

2.3 Allowing Unsecure T.38 with Secure RTP

Context

The T.38 protocol must be enabled under Media /Codec .

This procedure is required only if SRTP is used and is available provided the Select Endpoint selection list is set to Default .
Steps
  1. Go to Media /Security .
  2. In the Security table, under the RTP section, set the Mode selection list to Secure with fallback .
  3. Under the T.38 section, set the Allow Unsecure T.38 with Secure RTP selection list to Yes .
  4. Click Apply .
Result
Top

2.4 Modifying the SRTP Basic Port

Steps
  1. Go to Media /Misc .
  2. In the Base Ports table,in the filed next to SRTP , indicate in the field to first port to use in SRTP.
Result
The first port to be used in SRTP will be the one specified.
Top

3 Advanced RTP Parameters

Although the services can be configured in great part in the Web browser, some aspects of the configuration can only be completed with the configuration parameters by :
  • using a MIB browser
  • using the CLI
  • creating a configuration script containing the configuration parameters
For more details refer to the DGW Configuration Guide - Reference Guide published on the Media5 documentation portal https://documentation.media5corp.com/ .
  • Mipt.EnforceSymmetricRtpEnable : To enforce symmetric RTP.
  • Mipt.SessionUpdateCryptoMode : To psecify if the cryptographic parameters should be regenerated or not after a hold/resume scenario in SRTP.
  • Mipt.InteropPacketReceptionMode : to select the modes that control the type of processing applied at the reception of RTP packets.
Top

4 Online Help

If you are not familiar with the meaning of the fields and buttons, click Show Help , located at the upper right corner of the Web page. When activated, the fields and buttons that offer online help will change to green and if you hover over them, the description will be displayed.

Top

5 DGW Documentation

Mediatrix units are supplied with an exhaustive set of documentation.

Mediatrix user documentation is available on the Documentation Portal at http://documentation.media5corp.com

Several types of documents were created to clearly present the information you are looking for. Our documentation includes:

  • Release notes : Generated at each GA release, this document includes the known and solved issues of the software. It also outlines the changes and the new features the release includes.
  • Configuration notes : These documents are created to facilitate the configuration of a specific use case. They address a configuration aspect we consider that most users will need to perform. However, in some cases, a configuration note is created after receiving a question from a customer. They provide standard step-by-step procedures detailing the values of the parameters to use. They provide a means of validation and present some conceptual information. The configuration notes are specifically created to guide the user through an aspect of the configuration.
  • Technical bulletins : These documents are created to facilitate the configuration of a specific technical action, such as performing a firmware upgrade.
  • Hardware installation guide : They provide the detailed procedure on how to safely and adequately install the unit. It provides information on card installation, cable connections, and how to access for the first time the Management interface.
  • User guide : The user guide explains how to customise to your needs the configuration of the unit. Although this document is task oriented, it provides conceptual information to help the user understand the purpose and impact of each task. The User Guide will provide information such as where and how TR-069 can be configured in the Management Interface, how to set firewalls, or how to use the CLI to configure parameters that are not available in the Management Interface.
  • Reference guide : This exhaustive document has been created for advanced users. It includes a description of all the parameters used by all the services of the Mediatrix units. You will find, for example, scripts to configure a specific parameter, notification messages sent by a service, or an action description used to create Rulesets. This document includes reference information such as a dictionary, and it does not include any step-by-step procedures.

Top

6 Copyright Notice

Copyright © 2019 Media5 Corporation.

This document contains information that is proprietary to Media5 Corporation.

Media5 Corporation reserves all rights to this document as well as to the Intellectual Property of the document and the technology and know-how that it includes and represents.

This publication cannot be reproduced, neither in whole nor in part, in any form whatsoever, without written prior approval by Media5 Corporation.

Media5 Corporation reserves the right to revise this publication and make changes at any time and without the obligation to notify any person and/or entity of such revisions and/or changes.

Top