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Adrian Georgescu, 08/29/2013 04:37 pm

SIP2SIP Data Privacy and Storage Policy

SIP2SIP server infrastructure relays and stores information provided by end users. If you are concerned about privacy of your own data and how it is used inside the platform, read below.


As any Internet server based infrastructure, you can forget about privacy when using any server. Everything that goes through a server is subject to forces outside the control of the clients using it. So you may safely assume all data exchanged through the server is compromised by design. If you care about privacy of your data you should find clients that reveal as less data as possible, then encrypt all the data that is possible to encrypt and never share the private key used to encrypt data with anyone.

SIP Accounts

SIP accounts and related information are stored in the platform database. SIP account and SIP Settings web page passwords are stored in an encrypted form in the database. There is a salt involved but in case of the database being completely compromised the salt can be also retrieved. It is advisable to use strong passwords that cannot be guessed by dictionary brute force attacks.

Account Deletion

You may request deletion of your account. If no commercial services have been purchased we will delete the account from the server database. If anything has been purchased, we will not delete the data as we are forced by law to keep records of all monetary transactions for up to seven years after purchase.

SIP Signaling

Signaling can be done in clear text using UDP and TCP protocols. You may use TLS for encrypting data between the end points and platform SIP servers. There is no guarantee that encryption will work end-to-end, the SIP signaling part of the platform provides only hop-by-hop signaling security, any intermediate hop may decide to switch from TLS to a non-encrypted transport like UDP.


All SIP signaling for session establishment (INVITE/BYE/CANCEL/PRACK/ACK SIP methods and their replies) relayed by the platform SIP servers are stored in cleartext for the last thirty days in platform databases. Both end-users and platform operator have access to this information for troubleshooting purposes.


No registration information (SIP REGISTER method) is stored in the platform.


No presence dialogs (SUBSCRIBE/NOTIFY methods) and related XML payloads are not stored in the server databases. Short logs about which device or subscriber changes its presence state are stored for up to thirty days for troubleshooting purposes.

Call Detail Records

Call Details Records (CDRs) are stored for up to six months in clear text format in platform databases. CDRs contain metadata information about who called whom and what time and for how long. The IP addresses used for signaling and media are also stored in the CDRs.

Offline Messaging

Text Messages

Messages sent using SIP MESSAGE method that cannot be delivered to local users of the platform are stored for later delivery in cleartext format in the platform database.


Voicemail message are sent un-encrypted over email as attachments and stored un-encrypted on the server voicemail server (optional). Voicemail can be enabled/disabled for each SIP account.

RTP Media

RTP streams are relayed by platform RTP media relays. Actual data is not stored anywhere. You may encrypt your data using sRTP but the encryption key is available in the SIP signaling. Whomever has access to the signaling plane (and the server always has access to it) will be able to decrypt any sRTP encrypted stream. If your end-points supports zRTP, is much safer than sRTP as the decryption key is known only by the end-points.

MSRP Media

Chat Messages

MSRP chat sessions are done over TLS connections via the platform MSRP relay servers. The content of the messages is not logged or stored anywhere.

Blink users can replicate the chat messages between multiple instances configured with the same account. The replicated chat messages are stored for 60 days in encrypted form in platform databases. The encryption key is not known by the server, only Blink clients posses the encryption and decryption key. If you are concerned about privacy you may disable chat replication in Blink.

File Transfers

MSRP file transfer sessions are done over TLS connections via the platform MSRP relay servers. The content of the files is not logged or stored anywhere.

XMPP Gateway

All chat messages and presence payloads are relayed through the SIP/XMPP gateway. Message content is not stored anywhere.

Protecting Data and Privacy

Illegal Intercept

We do our best to store your data securely and not expose it unless necessary for the operations of the platform. You can also help in this process.

To protect your data against being exposed over the Internet (like IP tapping), do the following:

  • Use TLS for SIP signaling
  • Use zRTP for audio and video media if your end-points support it otherwise use sRTP
  • Use TLS for MSRP media
  • Us OTR for Chat

These would protect your data against those who try to illegally sniff your network traffic (like breaking into your LAN WiFi) but have no access to the client or server software. These measures will not protect your data privacy against legal intercept measures if enforced and applied to the server infrastructure that relays the messages (you will likely not know if and when this happens).

Legal Intercept

In case any entitled government agency requires access to the meta-data stored by SIP2SIP infrastructure, all SIP account data stored on the server can be considered compromised.

To minimize the chance of your SIP sessions and media being exposed in case of legal intercept has been enforced do the following:

  • Use ICE in both end-points, this way RTP streams can flow most of the time peer to peer without passing through the server media relays
  • Use zRTP encryption, this way you will know about men in the middle attacks trying to intercept and decrypt your data
  • Don't use SIP MESSAGE method
  • Don' use MSRP media unless you have a client that has additional media encryption where the key is not known by the network


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