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BT Unified Trading
architecture
Contents
BT Unified Trading
Key components
BT Unified Trading voice service
Customer site configuration
Component description
BT Unified Trading collaboration server
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BT Unified Trading architecture
BT Unified Trading
BT Unified Trading is an end-to-end set
of tools and services that fit the evolving
trading landscape. It provides market
participants with the solutions they need
to retain and grow clients and flex their
business technology, within an evermore
rigorous regulatory environment.
BT Unified Trading is an integrated solution for: • Communication
• Collaboration • Compliance
BT’s ground-breaking offering enables market participants to interact, collaborate and trade over multiple channels, including voice, IM, email, video and SMS, securely and compliantly. Integrated with the BT Radianz cloud, the leading financial markets network serving more than 15,400 connected sites across more than 60 countries.
The BT Radianz cloud is the leading connectivity and hosting platform for financial firms around the world. It supports 15,400 financial customer locations across the globe, providing connectivity to more than 400 of the world’s leading financial content and service providers. Customers benefit from low latency access to market data, trade execution, and trade cycle applications and services.
BT Unified Trading
How the markets interact: voice
How the markets interact: data
BT Unified Trading leaves behind the old world approach of voice and data silos for a new era
where voice and data are combined in a single end-to-end solution.
BT Unified Trading architecture 4
BT Unified Trading
BT Unified Trading
BT Unified Trading is a key chapter in
the implementation of BT’s vision for
trading communications. By bringing
together voice and data across BT’s award
winning Radianz cloud you benefit from
a powerful new set of solutions, designed
to address the challenges you face today.
This new integrated architecture provides
a high-speed, secure and stable platform
enabling your clients to collaborate and
communicate across multiple channels.
Key features this architecture are:
• Flexibility
• Built on standards-based open technology, this highly innovative architecture introduces a new level of agility for supporting trading operations, particularly those dispersed across a region
• Scalability
• The platform is highly scalable and capable of supporting many thousands of users equipped with trading turrets • Switchless
• Breaking down the barriers of physical and proprietary hardware switches, the new technology reduces the data center space requirement – saving space, power and CO2 emissions
The key components of BT Unified Trading are:
• Communication:
• BT Unified Trading voice service • BT Unified Trading session manager • Collaboration:
• BT Unified Trading collaboration server • Compliance:
• BT Unified Trading recorder
The components are compatible with the state-of-the-art BT Netrix desktop device, designed for the rigorous demands of the trading floor, and are delivered by BT’s dedicated and experienced global team that continues to provide ongoing managed services for the global estates of some of the world’s largest investment banks.
Each of the key components are described in the following sections.
BT Unified Trading architecture 6
The BT Unified Trading voice service gives you the reliable and “always on” access to
the markets of traditional point-to-point private wire voice circuits, but with far greater
flexibility for supporting the distributed trading floors and remote data centres of a modern
trading environment.
BT Unified Trading voice service is a SIP/IP service in the core network with IP/SIP interfaces into your trading floor; it also provides E1/T1 gateways to existing voice trading switches and TDM trader voice networks, ensuring you stay connected to your existing community and can migrate your current TDM trading floor infrastructures at a pace that makes sense for your business.
The solution architecture is made up of five main elements each inter-working to provide the overall service. These are as follows:
• Signalling Centre • Border Gateway • Voice Gateway • LDAP directory
• BT Unified Trading portal
Signalling Centres
Signalling Centres (SC) are located in the BT data centres and form part of the Session Border Control (SBC) functionality. Their primary purpose is to authenticate and establish voice connections between two end-points when call requests are received. They interact with the LDAP directory to authorise and authenticate SIP requests (e.g. Register, Invite) and must be co-located with the LDAP on a LAN. Any Signalling Centre can be used to establish a call and as part of this process they assign the nearest Border Gateway to be used for that voice connection thereafter. Once a voice connection is established successfully, the SC’s role is complete and it is no longer required for that individual connection, unless unintended disconnection occurs, i.e. in the event of failure or upon instruction to invoke a DR Plan. In each instance, an SC is a pair of ACME packet devices configured for High Availability.
Border Gateways
Border Gateways (BG) are located in BT data centres and form part of the Session Border Control (SBC) functionality. Their primary purpose is to control the flow of media (voice) across the network for in-service voice connections. BG therefore need to be present throughout the life of a voice connection. They provide secure voice communication by ensuring only authorized traffic receives voice-class service. The Signalling Centre assigns the BG to a voice connection during the call set-up based on distance from the A-end site, with the nearest being selected. Each instance of BG is a pair of ACME packet devices configured for High Availability (HA). Should one of the HA pair fail, the second device will be brought in, with failover taking less than 1 second, causing minimal impact to live calls. Should both devices in the HA pair fail, a new call will automatically be generated and routed through an alternate BG in that city. There are two instances of BGs installed in diverse PoPs in each of the major trading centres around the world.
Voice Gateways
Voice gateways are typically located on a customer site, inside the CE router. However, they can also sit behind the CE router in a cascaded topology. In the case of a hybrid IP/TDM solution delivered via an IP/TDM gateway, the voice gateway itself will be located in a BT data centre as opposed to on a customer site. The role of the voice gateway is to establish voice connections and convert CAS traffic into IP. The voice gateway contains a media card which does not perform a failover activity, however the cards are extremely reliable and one of the least likely components to fail. To minimise risk, multiple voice gateways can be used to spread the voice connections thus reducing the impact of any failure.
LDAP Directory
The LDAP Directory is a database that is physically located in a BT data centre alongside the Signalling Centre, and logically replicates its data around the network. It is the reference store that the SC uses to retrieve information for authenticating and routing calls. It then stores and maintains a directory of all the BT Unified Trading voice service customers, and their respective voice connections. There are multiple physical instances of the LDAP, with one instance co-located within each of the Signalling Centres. Firms do not have direct access to the LDAP directory and instead access the relevant contents of the directory via the BT Unified Trading portal interface.
BT Unified Trading portal
The BT Unified Trading portal is powerful web-enabled tool allowing customers to self-provision voice connections, create/invoke Disaster Recovery plans and view their online inventory of voice connections at any time. It interfaces with the LDAP directory to create/receive call requests for new voice connections.
BT Unified Trading architecture 8
The voice gateway is the component of the BT Unified Trading voice service, situated on the customer site if a T1/E1 handoff is required (as opposed to SIP/IP handoff). For IP/TDM hybrid solutions, this gateway is located in a BT data centre.
The gateway configuration installed will vary from customer to customer, but the right solution will be designed at the outset of the initial order. There are a number of factors that influence which solution is installed at each site, such as:
• Call volume: the number of voice connections required at that site. Both outbound and inbound should be considered • Growth: what the mid- to longer-term growth requirements
are for that site
• Scaling: the number of calls that should be supported on a single device or port within a device
• Disaster Recovery: whether the site is required as a DR location exclusively or in combination with another site • Existing environment: whether the site on the BT network
has a compatible device already
The BT Technical Solutions Consultant will work with each organisation to design and tailor the right solution. Sometimes this can be a complex process, and will be influenced by many variables affecting the total number of voice connections supported by a given solution. This includes:
• Resilience: i.e. is there one or two access legs on the Wide Area Network (WAN)
• Cascaded or integrated device: is the Voice Gateway going to be inside the CE or cascaded behind it?
• Access circuit type: is the WAN a Leased Line or Ethernet? • Physical Ports: how many physical ports are present at the
south side of each device?
• Consolidated Voice/Data: will this solution support both voice and data services?
Whilst each customer solution is scaled and designed to meet the precise requirements of the business, the common denominator in every voice gateway is its function for performing the conversion of CAS traffic to IP packets, both on ingress to and egress from the network.
The current voice gateway has been developed using Cisco ISR model routers. They can be deployed as an integrated solution, i.e. inside the CE router, or as a cascaded solution, i.e. behind the CE router. A CSI switch will be provided for cascaded solutions. The following devices are currently supported:
• ISR 2911: integrated or cascaded behind ASR 1002 • ISR 3945: integrated or cascaded behind ASR 1002 • ASR 1002: not a VG but used in cascaded topology as CE By default, BT will install resilient infrastructure at all A-end sites and non-resilient infrastructure at all B-end sites. Note that organisations can request resilient infrastructure at the B-end sites, however a surcharge may be applied. For resilient topologies, resiliency is inherently built into the IP solution, however, the TDM port on the south side of a voice gateway is not resilient. The connectivity beyond the voice gateway, i.e. from the south side port into the customers’ voice switch environment, is beyond the purview of the BT Unified Trading voice service.
The total number of calls supported by each solution varies enormously given the number of determining factors. In some cases, for the larger sites that require a high volume of voice connections to be supported, a cascaded solution will be necessary.
Fig 1 - Non-resilient
Fig 2 – Resilient
Integrated Voice Gateway
Integrated Voice Gateway
Cascaded Voice Gateway
These diagrams show a simple view of both the integrated and cascaded topology types. Both non-resilient and resilient views are included for completeness.
BT Unified Trading architecture 10
The BT Unified Trading session manager components are:
• SIP Registrar & Call Controller • Administration
• Media Servers providing the conferencing resource • SIP-based user devices, including BT Netrix
• Media Gateways for terminating traditional TDM/Analog lines • Session border controllers securing access to external
SIP trunks
• Voice Recording Servers
The following is a description of each component within the architecture:
1. SIP Registrar and Call Controller environment is hosted on a series of load-balanced Linux Servers, mirrored across dual data centre clustered environments to ensure resiliency. Each implemented cluster is responsible for a set of turrets, recording servers, conference servers, gateways & SIP trunks. Clusters work together with a common database to support free-seating and high availability.
The servers in the cluster can be distributed between two metropolitan data centres provided the round trip delay across the network is under 2ms.
Integral to the clustering is the use of a third party virtual IP address load balancer (VIP). The VIP routes SIP requests to individual servers in the cluster so that the load is balanced across servers, and should a server fail, the load is evenly distributed across the rest of the environment. BT’s application software runs within a JAIN SLEE
container. JAIN SLEE is a Java standard geared towards the handling of large-scale, performant, event-based systems and is used extensively in modern carrier-grade networks handling SIP communications.
The session manager supports web services interfaces (XML, HTML) for management and application integration.
2. Network Gateways – BT Unified Trading voice service makes use of standard SIP gateways to enable termination of TDM and analog lines. The BT Unified Trading platform is fully tested with gateways from Cisco, Audiocodes and Vegastream.
Common channel trunks such as QSIG and ISDN are much standardised and off-the-shelf gateways cover all the major features used by BT Unified Trading voice service. Fixed channel trunks conform to BT’s CAS implementation over SIP standard which has been registered with the ietf at https://datatracker.ietf.org/doc/draft-beauchamp-private-wire/
BT Unified Trading session manager
component description
3. The media server component provides the conferencing resources in the platform. BT currently uses commercial media servers that support the SIP protocols for conference handling – MSML and MSCML.
The media server is treated as a simple Digital Signal Processing (DSP) resource with the specialist conferencing functionality configured by the session manager.
For the majority of installations a software-based media server is hosted on standard servers. For large trading floors specialist hardware is adopted to meet the performance requirements.
4. User Devices – BT Unified Trading session manager has been designed to interface with numerous user devices, including BT Netrix specialist trading floor devices.
BT Netrix is a Linux processing environment with DSP audio handling for up to 27 audio channels. BT has engineered a SIP overlay to support dual streaming whereby a copy of the audio is sent directly to the voice recorder, and even triple media streaming for N+N recording. The overlay supports a mixing of handset and speaker channels with optional compression prior to delivery to the voice recorder. The SIP overlay also supports encryption of all audio through S-RTP and compression to G.729b as well as other codecs.
5. SBC - SIP Trunks.
The platform can accept registration directly from external SIP trunks. For trunks sourced from internal systems, such as the PBX, connectivity would most likely be direct; however for externally sourced trunks, BT expects that there would be a Session Border Controller (SBC) in the path.
6. Voice Recording Servers are supported using a method of Dual Media Streaming from the turrets across the LAN/ WAN. Essentially, the turrets initiate a SIP call to the voice recorder at the point when the user logs in.
The SIP call is made via the session manager that allocates the recording server based on location and user compliance requirements. The media then flows directly from the turret to the voice recorder. The call ‘metadata’ is passed within the SIP message flows, eliminating the need for a separate CTI interface.
BT Unified Trading session manager
component description
BT Unified Trading architecture 12
BT Unified Trading collaboration server
brings Computer Telephony Integration
(CTI) into a Web 2.0, collaborative, open
source and multi-channel environment.
The BT Unified Trading collaboration server consists of a server-based application that provides a platform layer that sits between enterprise applications and their communications infrastructure.
BT Unified Trading collaboration server provides a standard API – the BT Unified Trading api – to enable enterprise applications to tightly integrate communications with their business workflow.
BT Unified Trading collaboration server uses Openfire, an open platform that provides a flexible plug-in architecture, to
connect to a broad array of communications infrastructure including: BT Netrix, Cisco CallManager, Avaya PBX, Microsoft LyncTM and OCS/Lync. BT Unified Trading collaboration server
uses these plug-ins for CTI control of the platforms as well as to obtain access to the user profiles and configuration data in the communications infrastructure.
A key benefit of this approach is that it provides a single and uniform API application which hides the complexity of a heterogeneous and potentially multi-versioned communications environment from application developers. Their applications, therefore, can readily benefit users across the entire enterprise, regardless of the communications platform that they may be using.
BT Unified Trading collaboration server provides a text messaging capability that enables chat rooms, archiving of chat sessions and proxy messaging gateways to Reuters Messaging, AOL®, Yahoo®, MSN® and Google Search. In addition, BT Unified Trading collaboration server provides a voice drop and voice blast capability, allowing analysts and sales staff to play messages for clients, or easily leave a message if the client is unavailable. Voice drop allows an end user to play individual or multiple messages (or parts of messages) for a single client, and voice blast allows the user to specify a list of clients to send messages to.
Finally, BT Unified Trading collaboration server also
orchestrates video collaboration so users can join multiparty video conferencing. BT’s implementation has many benefits. Leaving the audio on the underlying voice platforms, it requires no changes to the current methods of recording of calls. It also provides browser-based video so that no special software is required at end user desktops.
1. Architecture Overview – Unifying Three Domains
The BT Unified Trading collaboration server brings together three domains:
• Trader voice and telephony infrastructure • Business applications
• External communities and clients
By joining these domains and providing rich desktop and mobile User Interfaces, end users dramatically increase their ability to collaborate with their colleagues, customers and partners.
The BT Unified Trading collaboration server is built on an open source XMPP messaging platform called Openfire, which provides a powerful, scalable and resilient
messaging exchange, capable of powering business-class collaborative communications.
The platform is plug-in based, with plug-ins added in the standard manner for each type of communications infrastructure that forms part of the customer’s collaborative environment, including BT Netrix and the BT Unified Trading session manager, PBXs such as CiscoTM, Avaya and Nortel, as
well as Microsoft® LCS, Microsoft® OCS, and Microsoft® LyncTM platforms.
At the crux of the BT Unified Trading collaboration server is the collaboration graph that consists of user profiles, their interests and associated devices. Coupled with a scalable publish-and-subscribe approach, BT Unified Trading collaboration server is able to keep users and business applications constantly aware of all the communications that are relevant to the individual or the situation.
2. Video, IM, Voice Drop and Blast
The BT Unified Trading collaboration server also includes a highly scalable video collaboration function allowing users to participate in multiparty video arrangement with other users from around the globe. Voice is still carried on the trader voice platform, and all the voice recording and compliance tools remain unchanged.
The BT Unified Trading collaboration server is
fundamentally a XMPP messaging server that has its roots in highly scalable Instant Messaging. As such, it provides trading environments and enterprises with a private IM capability, complete with group chat and compliance archiving. In addition, BT Unified Trading collaboration server provides proxy gateways to external IM communities (Reuters, AOL, Yahoo!, MSN, and Google.)
The BT Unified Trading collaboration server also includes a powerful Voice Drop/Voice Blast function that allows users to record messages and then play them or “drop” them to voicemail systems. An easy-to-use User Interface allows the function to be called up during any call so users can operate efficiently, and clients may receive critical information in a timely fashion.
Offices worldwide
The telecommunications services described in this publication are subject to availability and may be modified from time to time.Services and equipment are provided subject to British Telecommunications plc’s respective standard conditions of contract. Nothing in this publication forms any part of any contract.
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