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eXpress Federation Architecture

eXpress Federation Architecture

Corporate and public servers are united in the common eXpress federation:


eXpress Servers Federation

What is the eXpress Federation?

It's a network of regional and corporate eXpress servers. It includes all public regional (
RTS
) and corporate (
Lite
,
CTS
) servers and some enterprise servers (
ETS
,
eCTS
), which have it's own customized version of the app.

What Does the Federation Offer?

Within the federation, users of different organizations can:

  • Exchange messages and files
  • Schedule conferences and calls
  • Interact with users from other companies

Regional Transport Server, RTS

RTS

It is a public cloud server. In eXpress, RTS affiliation is indicated by green icons for contacts and servers.

For Administrators: Purpose & Features of RTS

Purpose of RTS

  • Global routing of messages between all members of the federation (both corporate and external users) in any apps;
  • Initial user registration on
    RTS
    ,
    Lite
    ,
    CTS
    (including working with SMS codes), and guest profiles;
  • Sending push notifications to eXpress client apps for
    RTS
    ,
    Lite
    ,
    CTS
    users.

Features of RTS

  • There are several such servers located in Russia at the disposal of the eXpress vendor.
  • You can register on
    RTS
    for free via personal non-corporate account in eXpress, but the app's capabilities will be limited in such case.

Who Administrates the RTS?

Server-side administration is handled by eXpress support.

Corporate Transport Server, CTS

Lite
CTS
A corporate server is at some company's disposal (maybe even where you are working). In eXpress,
CTS
affiliation is indicated by blue icons for contacts and servers.
  • Lite
    corporate server is a
    CTS
    corporate server with limited functionality.
  • A corporate server that follows
    ETS
    instead of
    RTS
    is called
    eCTS
    .
For Administrators: Purpose & Features of CTS/eCTS

Purpose of CTS/eCTS

  • Authentication of corporate users and guest profiles (if configured);
  • Routing and storing files and messages of corporate users;
  • Corporate phonebook;
  • Direct interaction with other corporate servers (of this organization or a partner organization);
  • Other functions for corporate communications (conferences, bots, etc.).

Features of CTS

  • CTS
    provides basic messaging functions within an isolated, secure corporate network. Employees of the organization need to register on the corporate server to communicate with each other.
  • All
    CTS
    (and
    Lite
    ) servers are connected to
    RTS
    directly and use it for registration and sending push notifications.
  • An organization may have several corporate
    CTS
    servers, and trusted connections (trusts) can be established between them. Users from one trust server can search for users from another, and traffic is routed directly between trust servers, bypassing the intermediate
    RTS
    .

Who Administrates the CTS?

Server-side administration is handled by your organization support, or by partner, or by paid eXpress technical support.

Can a Regular CTS Be Disconnected From the Federation?

Isolated operation of
CTS
is not possible.

Enterprise Transport Server, ETS

ETS
The enterprise transport server unites corporate servers (in this case they may be designated not
CTS
, but
eCTS
) of a large interregional enterprise into a “mini-federation”. It can be called an analogue of a
RTS
that unites several
CTS
. This server is at some company's disposal (maybe even where you are working).
ETS
affiliation is indicated by blue icons for contacts and servers.
For Administrators: Purpose & Features of ETS

Purpose of ETS

  • ETS
    takes over the functions of the public
    RTS
    server for the branded app;
  • Routing of messages between users, allowing employees of one
    eCTS
    to communicate securely with employees of another
    eCTS
    ;
  • Initial registration of users within the organization’s contour (including working with SMS codes);
  • Sending push notifications to branded client apps within the organization.

Features of ETS

  • ETS
    installation occurs exclusively within the organization's perimeter.
  • The organization independently manages security policies and contour access.
  • Customizable initial registration of users within the organization’s contour.
  • Users are connected to
    ETS
    using a dedicated ETS client app, which is distributed by the organization. It's code can be additionally pre-checked before publishing to app stores.
  • Users can not stay on the
    ETS
    , it is required to register on eCTS.
  • RTS
    users can register on the
    ETS
    client app. If the user was a corporate user in eXpress, a logout is required, otherwise an error is displayed.
  • Users' phonebooks are stored on
    ETS
    .
  • ETS
    is independent of
    RTS
    , but is linked to
    RTS
    by default so that
    ETS
    app users could communicate with RTS and other
    CTS
    users. New
    eCTS
    are created on
    ETS
    , and
    RTS
    “does not know” about them. Autonomous operation of
    ETS
    in complete isolation is also possible.

Who Administrates the ETS?

Server-side administration is handled by your organization support, or by partner, or by paid eXpress technical support.

Server Interaction in the Federation

Below is a brief summary of how servers interact within the federation, with references to the relevant FAQ articles.

What Unites Servers in the Federation?

  • Routing of messages, files, and calls.
    RTS
    acts as a global gateway for all types of traffic between non-trust
    CTS
    and for traffic to/from public users.
    ETS
    performs a similar role inside an enterprise's “mini-federation” for its
    eCTS
    servers.
  • End-to-end user identification using HUID, provided by
    RTS
    or
    ETS
    .
  • Trusted connections (trusts). A trust connection can be established between a pair of corporate servers (
    CTS
    /
    eCTS
    — from the same or different organizations). Trust servers enable direct traffic exchange bypassing
    RTS
    , trust search for users, and extended permissions for invitation links and files from within the corporate network (CDTN).
    For Administrators: How to Manage Trusts
    CTS
    eCTS
     Management is performed by the administrator on the Trusts tab in the admin panel.
  • Distributed storage of chats and files. Each interserver chat/channel, interserver calls and conferences recordings, and shared files are replicated to the servers of all participants — see “Storage and Deletion of Chats” and “Files”. This also explains the visibility of history when adding a new participant from a “fresh” server — see “Chat History”.
  • Isolated
    ETS
     does not participate in the common federation: its users cannot see users from
    RTS
    /
    CTS
    /other
    ETS
    servers, and vice versa — see the definition of “Isolate”.
  • Emergency mode of a corporate server when the root server is unavailable disables trust connections and interaction with external users — see details below.
  • eXpress global chat is the only system chat that comes from
    RTS
    to all federation users; the administrator of a specific corporate server can disable it locally — see “Global Chats”.
For Administrators: How to Configure My Server to Operate in the Federation?
CTS
ETS
eCTS
 Details on administering trusts, network perimeter restrictions, and links with public / corporate / trust access levels can be found in the admin panel FAQ.
For Administrators: Corporate Server Emergency Mode When RTS Is Unavailable
Lite
CTS
eCTS
 If
RTS
becomes unavailable, a regular
CTS
/
Lite
server or an
eCTS
server subordinate to a non-isolated
ETS
enters emergency mode. In this state:
App Function
CTS
Lite
eCTS
(non-isolated
ETS
)
Registration and login of new corporate users Not working (current sessions remain active) Working, but a synchronization queue with the federation builds up
SMS code verification Not working Working
Push notifications Not working Working (except when push notifications are proxied through
RTS
)
Synchronization of user public keys Not working Working, but a synchronization queue with the federation builds up
Trusted server connections Working as long as authentication tokens are valid Working
Creating chats, calls, and conferences Working as long as authentication tokens are valid, but only with users from this server and trusted servers. Guests must be created on this server — more details. Working, but only with users from this server and trusted servers. Guests must be created on this server — more details.
Server contact directory Working as long as authentication tokens are valid, but becomes outdated over time, and users from other servers start showing as "Unknown User" Working, but becomes outdated over time, and users from other servers start showing as "Unknown User"
Thus:
  • CTS
    /
    Lite
    server does not support fully autonomous operation     without a connection to
    RTS
    — access must be provided on both the corporate server side and the client side.
  • eCTS
    server in the federation (under a non-isolated
    ETS
    ) can operate without a connection to
    RTS
    for a certain period of time.
  • eCTS
    server under an isolated
    ETS
    normally operates without a connection to
    RTS
    .

How Does Traffic Flow in an Interserver Chat/Call?

Participant Composition Route
Single server (
CTS
/
eCTS
)		 Local only on the server
Only trusted
CTS
/
eCTS
 Directly between servers, bypassing
RTS
Non-trust corporate servers Via
RTS
At least one public (external) user Via
RTS
A visual diagram for a specific chat can be found in the chat properties > “Routing”.

What Is Needed to Communicate With Colleagues on Other Servers?

Typically, no additional steps are required, and you can immediately communicate with colleagues from other federates servers! For more details on finding colleagues, see this article. However, if your network connection has restrictions due to your organization's or network provider's policies, contact your organization's support team, partner, or administrator, or your provider, to grant network access to your devices.

How to Switch to an Isolated Environment?

To disconnect from the eXpress federation, your organization needs to deploy and configure an
ETS
server with the purchase of the appropriate license.