In this section:

Use the DTLS Profile window to configure various DTLS parameters to attach to a SIP trunk group in support of WebRTC functionality.

Similar to TLS, the Datagram Transport Layer Security (DTLS) protocol provides authentication, data integrity, and confidentiality for communications between two applications over an unreliable User Datagram Protocol (UDP) connection. The Secure Real-time Transport Protocol (SRTP) provides encryption, message authentication and integrity, and replay protection to the RTP data in both unicast and multicast applications. DTLS-SRTP is an extension to the DTLS protocol, where DTLS acts as the key management protocol. DTLS protocol is also extended to negotiate the SRTP crypto suites and parameters for use with those keys.

WebRTC is a signaling protocol defined for real-time communication between web browsers. WebRTC uses the DTLS-SRTP protocol for media exchange between browsers. The SBC includes the following functionality:

  • Real-time communication between web browsers using DTLS-SRTP while inter-working with SIP networks.
  • DTLS on the media path for key management for SRTP-based media.
  • Self-signed certificates to secure and authenticate DTLS associations. DTLS connections are secured by the two browsers sharing self-signed certificates as part of the media connection during a DTLS handshake between the browsers. The certificates are authenticated by checking a fingerprint which is passed in the signaling path as part of the Session Description Protocol (SDP) negotiation.

The SBC includes crypto suites that define a set of ciphers (algorithms used for encrypting data) which allow the selection of an appropriate level of security. When a DTLS connection is established, the client and server exchange information about which cipher suites they have in common.

To View DTLS Profiles

On the SBC main screen, go to All > Profiles > Security > DTLS Profile.

The DTLS Profile window opens.

DTLS Profile List Window

 

To Create a DTLS Profile

To create a new DTLS Profile:

  1. Click New DTLS Profile. The Create New DTLS Profile window opens.

    Create DTLS Profile Window

     
  2. Use the following table to configure the options and then click Save.

DTLS Profile Parameters


Parameter

Description

NameSpecifies the name of the DTLS Profile created. The value ranges up to 23 characters.

Handshake Timer

Specifies the time in which the DTLS handshake must be completed. The timer starts when the TCP connection is established. Must be 1 - 60 seconds; default is 5.
Session Resump TimerSpecifies the DTLS session resumption period for which cached sessions are retained (in seconds). DTLS allows successive connections to be created within one DTLS session and the resumption of a session after a DTLS connection is closed or after a server card failover, without repeating the entire authentication and other setup steps for each connection, except when the space must be reclaimed for a new session. Must be 0 - 86,400 seconds; default is 300.

Cipher Suite1 * 

Cipher Suite2 * 

Cipher Suite3 *

Use this parameter to specify the first DTLS Cipher Suite choice for this profile.

  • nosuite
  • rsa-with-aes-128-cbc-sha (default) – Confidentiality cipher and mode for the DTLS Record protocol.

  • rsa-with-aes-128-cbc-sha-256 – Confidentiality cipher and mode for the DTLS Record protocol with SHA-256 as the hash function.

  • rsa-with-aes-256-cbc-sha – Confidentiality cipher and mode for the DTLS Record protocol with AES 256 encryption.  

  • rsa-with-aes-256-cbc-sha-256* – Confidentiality cipher and mode for the DTLS Record protocol with AES 256 encryption and SHA-256 as the hash function.

  • rsa-with-null-sha – The integrity cipher used for the DTLS Record protocol. 

  • tls_ecdh_ecdsa_with_aes_256_cbc_sha384** – Confidentiality cipher and mode for DTLS Record with AES256 GCM and SHA384 as hash function.

  • tls_ecdh_ecdsa_with_aes_256_gcm_sha384** – Confidentiality cipher and mode for DTLS Record with AES256 CBC and SHA384 as hash function. 

  • tls_ecdhe_ecdsa_with_aes_256_gcm_sha384** – Confidentiality cipher and mode for DTLS Record with AES256 CBC and SHA384 as hash function. 

    Modified: for 9.2.1

  • tls_ecdhe_rsa_with_aes_256_cbc_sha384* – Confidentiality cipher and mode for the DTLS Record protocol using ECDHE (Elliptic Curve Diffie-Hellman key Exchange).

  • tls_ecdhe_rsa_with_aes_128_cbc_sha  – Confidentiality cipher and mode for the DTLS Record protocol using ECDHE (Elliptic Curve Diffie-Hellman key Exchange) with AES128 CBC and SHA as hash function.

  • tls_ecdhe_rsa_with_aes_128_gcm_sha256 – Confidentiality cipher and mode for the DTLS Record protocol using ECDHE (Elliptic Curve Diffie-Hellman key Exchange) with AES128 GCM and SHA as the hash function.

  • tls-ecdhe-rsa-with-aes-256-gcm-sha-384* – Confidentiality cipher and mode for the DTLS Record protocol using ECDHE (Elliptic Curve Diffie-Hellman key Exchange) with AES256 GCM and SHA384 as the hash function.

  • tls_rsa_with_aes_128_gcm_sha256 – Confidentiality cipher and mode for the DTLS Record protocol with AES 128 GCM encryption and SHA-256 as the hash function.
  • tls_rsa_with_aes_256_gcm_sha384 – Confidentiality cipher and mode for the DTLS Record protocol with AES 256 GCM encryption and SHA-384 as the hash function.

* To use this cipher, DTLS version 1.2 must be enabled in the DTLS Profile.

** To use this cipher, DTLS version 1.2 must be enabled in the DTLS Profile and SSL certificates must be created using ECC keys.

Warning: When fips-140-2 mode is enabled, rsa-with-null-sha should not be used.

*Note: Up to three cipher suites can be specified in the profile.


Note

SBC releases 5.1, 6.2, and 7.2 are officially FIPS-compliant.

DTLS Role

 Specifies the allowed DTLS roles of this DTLS profile. The options are:

  • Client
  • Server (default)
Hash Type

 Specifies the allowed DTLS hash function for a specified DTLS profile. The options are:

  • Md5
  • Sha1 (default)
  • Sha224
  • Sha256
  • Sha384
  • Sha512
Cert NameSpecifies the name of the certificate referred by a specified DTLS profile. The default value is defaultDtlsSBCCert.
Cookie Exchange

Specifies the state that is, enabled or disabled cookie exchange.

  • disabled
  • enabled (default)
V1_0

DTLS protocol version 1.0.

  • disabled
  • enabled (default)
V1_1

DTLS protocol version 1.1.

  • disabled  (default)
  • enabled
V1_2

DTLS protocol version 1.2.

  • disabled (default)
  • enabled

To Edit a DTLS Profile

To edit a DTLS Profile:

  1. Click the radio button next to the specific DTLS Profile name. The Edit DTLS Profile window opens.
  2. Make the required changes and click Save.

To Copy a DTLS Profile

To copy a DTLS Profile and make minor changes:

  1. Click the radio button next to the specific DTLS Profile to copy.
  2. Click Copy DTLS Profile. The Copy DTLS Profile window opens.
  3. Make any required changes and click Save.

To Delete a DTLS Profile

To delete a DTLS Profile:

  1. Click the radio button next to the specific DTLS Profile that you want to delete.
  2. Click the Delete icon (X) at the end of the row. 
  3. Confirm the deletion when prompted.