Network Considerations for myAvail

Network Implementation Specifics

  • Why is IPv6 disabled?
    • Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 is intended to replace IPv4. By design the two protocols are incompatible. myAvail is designed to use IPv4 so we disable IPv6.
  • What ports are used for vehicle communications?
    • Port 10000 is used for the cellular connections
    • The IVU uses port 8085 to transfer data to and from the servers
    • The MDT uses ports 27020 and port 21 for FTP and any ports associated to passive FTP protocol
    • myAvail communicates over the http protocol normally over port 80
NOTE: These are the default ports and can be modified if needed. It is important to understand that myAvail uses FTP to move files from the servers to the vehicle IVU and MDT, which is required.
  • Are there any ports needed for internal server communications?
    • Yes, myAvail uses a number of methods to communication between the various components. These methods include socket connections which require an open port. Please consult the implementation team’s Systems Engineer for specifics on these ports. Reference Fig. 5 below for information on how the various components communicate.
  • What is the Security for Road Supervisor Laptops
    • The User must have access to the internal server that hosts the myAvail server.
    • The recommended method is though using a cellular modem that is connected to the Private Cellular VPN or through a standard company VPN access.
NOTE: This requires a very stable cellular connection. If the cellular connection drops the VPN is lost which causes the myAvail connection to drop. The end result is each time the cellular connection drops the user must log back into the VPN and to the application.

Alternate Connection Option: Is to use a firewall pass-through from a specific IP address to a specific external IP.

NOTE: While this communication option has drawbacks, it is more resilient to cellular disconnects as myAvail alone can automatically recover from brief cellular disconnections.
  • How to set router time out values?
    • Dead peer detection can cause problems by closing ports when Data traffic is absent for periods of time. DPD is a parameter for a point to point VPN connection between routers. We generally take the default of the router however this has caused problems. We prefer that DPD be off.
  • Considerations in setting up the Wireless Local Area Network (WLAN) for the Vehicles
    • The vehicle access should be on their own subnet\VLAN
    • The SSID must be broadcast
    • Each In-vehicle IVU needs an IP Address
    • Each In-vehicle MDT needs an IP Address
NOTE: In most cases this means there is a need for 2 IP Addresses per fixed route vehicle and 1 IP Address for each paratransit vehicle.
  • Considerations in setting up a cellular data network
    • Each cellular provider has different terms for the same functionality; therefore, it is important to be clear about which cellular provider is being discussed within any discussion about cellular service.
    • Static IP addresses from the cellular service is recommended
    • All the vehicle devices are recommended to be part of a VPN
      • This is required for hosted properties.
  • Considerations in setting up subnets
    • The in-vehicle equipment (IVU/MDT) can be on the same subnet
    • The myAvail server should be on a separate subnet
    • The cellular data connection should be on a separate subnet
  • How should remote facilities be connected?
    • Remote facilities should be set up with a permanent VPN tunnel
    • The bandwidth needs of the facility depends greatly on what needs to be supported at the facility. Please contact Avail Support if a new facility is being considered. Examples of various needs:
      • Vehicle WLAN for Bulk Downloads
      • myAvail Users
        • These could be dispatchers or planners who need to run large reports
      • Electronic Signs
        • LED signs with low bandwidth needs
        • LCD signs with high bandwidth needs
  • What capabilities/protocols are required of routers or switches?
    • Private connections to cell providers are typically done over IPSec Site to Site VPNs
      • If Verizon is the cellular data provider, then the BGP tunneling protocol is used with the VPN tunnel. Only a select group of routers support this protocol.
    • FTP download of vehicles requires passive FTP. This must be allowed through all routers.
  • Why does myAvail server need internet access?
    • The AVL server needs to access the internet to display map information to Dispatchers
    • To access the Gateway service and the text message service Clickatell
    • The TIDS server should be in a network DMZ as it is public facing
      • TIDS will need to talk to the myAvail server over at least one TCP port. This port is configurable.
  • What bandwidth do LED signs and LCD signs require?
NOTE: The data needs of electronic signs is dependent on the number of routes displayed on the sign and for LCD signs there is an additional factor of the possibility of having a second advertising or map frame. The following estimates assume 5 routes on the LED signs and 10 routes with no advertising or map included on the LCD sign. Please contact Avail Support for data needs when planning new electronic signage.
    • The fixed line LED sign runs @ 9600 Baud and uses ~ 20 MB per month of Data.
    • The full matrix LED signs use ~ 350MB per month
    • The LCD signs can use ~ 2GB per month
  • What should be considered when setting up a cellular data plan regardless of the number of vehicles?
NOTE: The Cellular plans are different for each Cellular provider and subject to change. Please check with the wireless provider for current plan options.
    • Several factors influence the size of the data plan needed for the vehicle communications. While 10 MB is a reasonable average, various needs could more than double that amount based on the following factors
      • Maximum time interval between AVL reports. Since passing a stop or moving a defined distance also triggers an AVL report, we usually set this value to 60 seconds. However, if a more frequent reporting rate is requested then the data needs will increase
      • Density of stops - In an urban setting where there is a defined stop every couple of blocks this will increase the data needs. Being in a rural setting where stops are widely separated may reduce data needs.
      • Electronic signage sharing the plan must be considered
    • Verizon - pools any plan under 150 MBs. Most properties have a few vehicles @ 150 and the rest @ 1 MB.
    • AT&T - only pools the same tiered plan. At least a 10 MB plan per vehicle is recommended based on a 60 second AVL reporting rate setting and a moderate stop density.
    • Sprint - pools any plan under 25 MBs. Most properties have few vehicles @ 25 and the rest @ 1 MB
NOTE: The concept of a pooled plan is simple, when devices share a common “pool” then the sum of all data assigned to each device is shared across all devices. As an example, if there are 10 vehicles with 150 MB purchased for 1 vehicle and 1 MB for the other 9 there is 159 MB that can be shared between the vehicles as needed.

Component Communication Methods

  • Figure 5 connection types
    • A - Native SQL Server protocol
    • B - TCP\IP - A proprietary custom written messaging using TCP/IP
    • C - Json (JavaScript Object Notation)/REST Endpoint (Representational State Transfer)
    • D - WCF/RIA Services Windows Communication Foundation
    • E - Web Services
    • F - FTP - File Transfer Protocol
    • G - Serial to IP to Serial using purchased devices to allow network (TCP/IP) connections
    • H - Dependent on the third-party package

Computer Network Term "DMZ"

In computer security, a DMZ or demilitarized zone (sometimes referred to as a perimeter network) is a physical or logical subnetwork that contains and exposes an organization's external-facing services to a larger and untrusted network, usually the Internet. The purpose of a DMZ is to add an additional layer of security to an organization's local area network (LAN); an external network node only has direct access to equipment in the DMZ, rather than any other part of the network. The name is derived from the term "demilitarized zone", an area between nation states in which military operation are prohibited.

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