Avail's Physical Infrastructure
The following diagram depicts a generic overview of the system and its components. It represents the multiple options available for system configuration.
Organization of Servers
This section provides insight into how Avail distributes the workload to ensure optimal system performance and other considerations related to server deployment. To find the recommended detailed server specifications, please consult Avail Support.
myAvail should be the ONLY product installed on these servers for the following reasons:
- Avail distributes functionality so that the recommended CPU and Memory is balanced and will accommodate all functionality at peak load times.
- Data Storage Capacity
- Avail provides data storage recommendations tied to the installed modules. The recommendations also consider redundancy and necessary through-out.
- Specific Software Version Requirements
- Avail uses various Microsoft and other common third-party tools in our product. Avail confirms that the correct versions of all third-party software are installed with the initial installation and during subsequent updates.
Avail recommends that the system configuration distributes all myAvail components across four to seven server instances with the physical servers connected by a network switch.
Network management depends on the property and varies considerably.
DATABASE SERVER (DB)
This server should support one instance of the MS SQL Server for only the myAvail databases. This server is the central repository of all system data and has the highest performance requirements. The performance of this server is critical to all aspects of the system.
COMMUNICATIONS SERVER (COMMS)
This server handles all myAvail related communications with all vehicles (fixed route, paratransit, supervisor, maintenance …). It supports the middleware between the in-vehicle solution and the in-office solution as well as other supporting functions.
AUTOMATIC VEHICLE LOCATION SERVER (AVL)
This server supports the core operational functions of myAvail, such as Dispatching and Yard Management.
INFO SERVER (USUALLY MERGED WITH AVL)
This server runs the DataPoint web application and supporting components, which provides the system setup, Route Schedule Maintenance, reporting, and data validation. Depending on the property size and server implementation, the Info and AVL servers can be merged onto a single server.
TRAVELER’S INFORMATION DATA SERVER (TIDS)
This server collects and prepares all data that are made available to the general public. The TIDS service acts as a common engine for all public facing data to ensure that all public data shows the same in-sync data regardless of delivery method (signs, text alerts, web page, or any other). TIDS is deployed in a network DMZ, meaning it is firewalled from the core “backend” modules and separated with another firewall designed to allow the public facing applications and modules to access system data. The separation of this functionality from the rest of the system is critical to overall security.
VOIP SESSION INITIATION PROTOCOL (SIP) SERVERS
These servers are the central processors in myAvail’s VoIP voice communications system and leverage Digium’s Asterisk VoIP solution platform. Asterisk is an open source framework for building communications applications across IP PBX systems, VoIP gateways, conference servers, and other custom solutions. Asterisk is used worldwide by small businesses, large businesses, call centers, carriers, and government agencies. There are more than one million Asterisk-based communications systems in use in more than 170 countries. Leveraging an open source architecture and existing standards helps future-proof the VoIP solution and provides a modular approach that is manageable for future expansion. Asterisk is a unified communications platform with broad capabilities and features that are widely adopted, mature, and robust.
This server should support only one instance of the MS SQL Server for myAvail’s data warehouse reporting database. This server is the central repository of all historical data and has the highest performance requirements. The performance of this server is critical to efficient reporting.
These servers can be implemented on individual hardware or in a virtual environment.
There are several considerations when planning the needs of on-site servers. Avail recommends using rack mount servers installed in a single rack, with one Keyboard, Video monitor, mouse, and a KVM switch to allow staff to service all the servers. Your property also needs an Uninterruptable Power Supply (UPS) to keep the servers running after a power failure. The size of the UPS depends on the equipment, other emergency power provisions, and the expected frequency and duration of power failures.
Another key consideration is the reliability and redundancy of data storage. Avail recommends using RAID 1, 5, or 10 for the disk arrays. Consider the property’s tolerance for system down time when deciding on the type of data storage and the on-site staffing that will be provided.
All operational/historical data reside on the Database server while only application executables and configuration files reside on the other servers.
To find the recommended specifications, please consult Avail Support.