BYOC with Talkdesk: Requirements & Limits

While Talkdesk BYOC is an advanced and highly adaptable solution, we recommend taking into account the following requirements and limits:



BYOC is currently available in the following regions: US, EU, APAC, and LATAM.

Number format conventions

Talkdesk BYOC SIP trunk establishment requires the E.164 number format with the following number convention:

  • ‘+’ ‘CC’ ‘NDC’ ‘SN’ (international)

  • ‘NDC’ ‘SN’ (national)

CC = Country Code

NDC = National Destination Code, identifying one or part of a PLMN (Public Land Mobile Network)

SN = Subscriber Number

Media and Signaling Cyphers and Crypto

  • Supported TLS Version: TLSv1.2 only. TLS v1.1 or previous is not supported.

  • Supported SIP Transport (SIP over TLS) Cipher Suite:

    • TLS_ecdhe_rsa_with_aes_256_cbc_sha384

    • TLS_ecdhe_rsa_with_aes_128_cbc_sha

    • TLS_rsa_with_aes_128_cbc_sha

  • Supported Media Transport (SRTP) crypto-suite:

    • AES_CM_128_HMAC_SHA1_80

    • AES_CM_128_HMAC_SHA1_32

  • No encryption: requires an explicit written request. 

Security & Encryption

  • Supported encryption methods:

    • TLS 1.2

    • IP Sec tunneling

    • AWS Direct Connect using TLS

  • No encryption: requires an explicit written request.


Inbound and Outbound verification are not provided by Talkdesk as this is the carrier’s responsibility. Only applicable in the US.

Outbound calls to extensions

  • Only supported in Europe in the following clusters/regions: Ireland eu-west-1 and Virginia us-east-1.

  • Short Number Dialing is not supported in the following clusters/regions:

    • EU2 (Paris eu-west-3 and Milan eu-south-1)

    • AP1 (Singapore ap-southeast-1 and Sydney ap-southeast-2)

    • US1 (Oregon us-west-2 and Virginia us-east-1) for accounts setup in Ribbon Session Border Controllers (SBCs).


Transcoding is not accepted to ensure the architecture's scalability and resilience.

CNAM (Caller Name)

Not supported.

Outbound calls via toll-free numbers

Not recommended.


Redundancy with Talkdesk Points of Presence (PoP) is mandatory for BYOC adoption. Applicable to all Talkdesk PoP regions.

Distinct IP addressing for media and signaling 

No media anchoring on the SBC is allowed to ensure scalability and resilience. All the media must be anchored on the architecture media servers, which means that distinct IP addressing for the signaling and the media must be supported by the carrier.

MKI (Master Key Identifier)

The MKI is currently not supported by our Media Server. This parameter must not be presented in the SDP crypto.

Lower case RFC MD5

The MD5 key configuration must be lower case. Upper case MD5 is not compatible.

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