# Presentation: 338359

## Accessible Telecommunication Systems

**Paul R. Michaelis, Ph.D., C.P.E.**
_**[prmichaelis@avaya.com](mailto:prmichaelis@avaya.com)**_
**October 11, 2006**

**Copyright © 2006 Avaya Inc. All rights reserved**
- Permission is granted for you to make copies of this document for legitimate government purposes, provided that the text is not altered and all references to Avaya are maintained.

## The goals of this presentation

**Review disability access laws and regulations that apply to the telecommunications industry.**
**Describe how, in my experience, the laws and regulations have been interpreted by government contract officers.**
**Describe some of the assistive devices that are commonly used with telecom systems.**
**Demonstrate products and solutions that improve the accessibility of telecom systems.  **
**Describe how these products work, thereby allowing you to see for yourself that accessible solutions don’t have to be expensive, complicated, or hard to administer.**

## With regard to “accessibility,” sometimes it seems like everyone has different goals.  Here are mine:

**Many of the people in my company who are working on accessible solutions have personal reasons for believing that accessibility is important.**
**We will not achieve our *****personal *****objectives if our solutions are adopted solely by organizations for whom Section 508 is mandatory.  **
**In the private sector, we have seen time and time again that the incremental costs and perceived complexity of accessible solutions are disincentives to the hiring of a qualified person with a disability.**
**For these reasons, whenever it is possible to do so, we embed our accessibility solutions within our mainstream products, and provide these solutions at no additional charge.**

## A quick review of assistive technologies:

**A quick review of assistive technologies:**
**(1) What is a TTY?**** **

## What is a TTY?

**A TTY (also known as a TDD) is a special text terminal that lets people who are deaf, hard of hearing, or speech-impaired use a telephone to communicate.**

## Some TTY basics

**There are *****many***** different TTY protocols.  **
**The one that’s most common in the US: **
**FSK “Baudot tones.”  Half duplex.  No error correction; no “handshake”; no carrier tone.  (TTYs are silent when not transmitting.)  There is no ability to interrupt the other person.**
**45.45 baud.  (Each “bit” is a 22ms tone, either 1400 or 1800Hz.)**
**Each character is a sequence of seven tones: a start bit at 1800Hz, five tones at 1400 or 1800Hz that specify the character, and 1.5 stop bits at 1400Hz.**
**Not all TTY users transmit *****and***** receive with their TTYs.  In fact, roughly half have hearing deficits, but still speak clearly.  These users often prefer to receive text and then speak in response.  This is commonly referred to as Voice Carry Over or VCO.**

## A quick review of assistive technologies:

**A quick review of assistive technologies:**
**(2) What is a **
**Telecommunication Relay Service?**** **

## Telecommunication Relay Service

**The purpose of a Telecommunication Relay Service, or TRS, is to be a “translator” between voice-based users of telecom equipment and people who cannot use traditional telephones because they are deaf, hard of hearing, or unable to speak clearly.**
**In the US, relay services may be accessed by dialing 7-1-1.  (NOTE: TRS calls to or from Federal agencies should use the Federal Relay Service, not 7-1-1.)**
**A recent estimate from Sprint TRS is that approximately 75% of their text relay calls involve translating between voice and 45.45 baud Baudot TTY.**
**Other assistive technologies that may be supported by TRS:**
**Text relay using TurboCode****TM, computer modems (typically 300 baud or 1200 baud ASCII), and IP-based Internet chat.**
**Video relay; useful for people who prefer sign language.**
**Voice supplemented by text captions (“CapTel”); useful for people who are hard of hearing. **

## A quick review of assistive technologies:

**A quick review of assistive technologies:**
**(3) What is inductive coupling***** *****?**** **

## Inductive coupling

**If an object gets within a few inches of most hearing aids, the aids often emit a loud howling sound.  This is simple acoustic feedback, similar to the feedback you can get with an auditorium P.A. system.**
**To prevent this when a phone is being used, the microphone in the aid must be turned off*****.  *****(Note: The microphone is turned off, but not the hearing aid itself.  Note also that not all assistive listening devices support this style of operation.)**
**The voice signal from the phone handset is transmitted to the aid via electro-magnetic inductive coupling. **
**Starting in 1989, all telephone *****handsets***** manufactured or imported for use in the US must have primary inductive coils.  The inductive coil in the assistive listening device that receives this signal is commonly referred to as a tele-coil or T-coil.  Note:**
**The regulations do *****not***** apply to headsets.**
**The electro-magnetic “noise” produced by many wireless devices makes it impossible to use inductively coupled assistive devices.**

## A quick review of assistive technologies:

**A quick review of assistive technologies:**
**(4) What are JAWS and Window-Eyes?**** **

## JAWS and Window-Eyes

**Computer users who are blind often rely on sophisticated text-to-speech screen-reading software adjuncts. Two commonly used products are JAWS****TM**** and Window-EyesTM.  Windows 2000 and XP include a primitive version of these products. **
***Try using this MS software to do your job:***
**Start > Programs > Accessories > Accessibility > Narrator**
- JAWS (“Java Access With Speech”) is a product of Freedom Scientific _[http://www.freedomscientific.com/](http://www.freedomscientific.com/)_
- Window-Eyes is a product of GW Micro _[http://www.gwmicro.com/](http://www.gwmicro.com/)_

## Relevant US laws 

**Relevant US laws **
**and regulations**** **

## First generation of disability access laws

**Architectural Barriers Act of 1968**
**First accessibility law; governed physical barriers (doors, stairs, etc.) in transportation facilities and Federal buildings. **
**Hearing Aid Compatibility Act of 1988**
**Requires the Federal Communications Commission to ensure that all telephones manufactured or imported for use in the United States after August 1989 are hearing aid compatible.  (In 2003, the FCC established a timetable for the development and sale of digital wireless telephones that are hearing aid compatible.)**
**Americans with Disabilities Act of 1990**
**Within the ADA, there are very few *****explicit***** requirements for telecom equipment.  (An exception is that Title IV of the ADA requires Telecommunication Relay Services to be available 24/7.)**

## Examples of recent telecom-specific laws

**Section 255,Telecommunications Act of 1996 **
- Empowers the Federal Communications Commission to require disability access provisions in telecom equipment and services.
**Section 508, Rehabilitation Act of 1973 **
**(As amended in 1998)**
- Adds specific accessibility requirements to Federal procurement regulations.

## Section 255, Telecommunications Act of 1996

**GOAL: ****Ensure that telecom equipment and services are accessible and usable by people with disabilities.**
**REQUIREMENTS:****  ****The US Access Board identified specific types of disability (e.g., complete or partial deafness, blindness, paralysis, cognitive impairments) and specific assistive devices (e.g., TTYs, inductively coupled hearing aids, cochlear implants); FCC rules require telecom manufacturers and service providers to take these disabilities and devices into account.**
**ENFORCEMENT:**
**The FCC is empowered to require compliance in all telecom products designed, built, or modified after February, 1996 *****if readily achievable*****.**
**Possible penalties for noncompliance include fines, loss of FCC product certification, and required retrofitting of the *****entire *****product line (not just the product that generated the original complaint).  **
**The FCC determines whether compliance is achievable.  There is no right of private action, i.e., *****the***** *****FCC’s decisions cannot be challenged in court*****.**

## Some definitions (Section 255)

**Readily Achievable**
**Easy to accomplish without unreasonable difficulty or expense, based on:**
**Incremental cost of the action needed.**
**Nature of action; don’t need to add technically infeasible features or those that fundamentally alter the product.**
**Overall financial resources of manufacturer.**
**Usable **
**Individuals with disabilities shall have access to the full functionality and documentation for the product, comparable to that provided to individuals without disabilities.**
**Accessible **
**Assessed by rating products on 19 different factors.  (These are listed in the next two slides.)**

## Input, control, and mechanical functions shall be locatable, identifiable, and operable...

**Without vision.**
**With low vision (between 20/70 and 20/200) and limited or no hearing, without relying on audio output.**
**With little or no color perception.**
**Without hearing.**
**With limited manual dexterity.**
**With limited reach & strength.**

**With a prosthetic device.**
**Without time-dependent controls, response time to be by-passed or adjusted.**
**Without speech.**
**With limited cognitive skills, cognitive memory, language, and learning skills.**
**(36 CFR 1193.41)**

## Information to operate and use the product

**Visual information must be available in an auditory mode.**
**Visual info must be accessible with low vision (20/200) without audio.**
**Auditory information must be available in a visual form and, where appropriate, in a tactile form.**
**Systems must provide support for inductively coupled hearing technologies, e.g.,***** *****hearing aids and cochlear implants.**
**Electro-magnetic interference with inductively coupled devices must be minimized.**
**Moving text must be accessible in a “static mode” at option of user.**

**Auditory information must be available to hard of hearing in an enhanced auditory fashion (e.g., increased amplification, signal-to-noise ratio)**
**Visual flicker must be reduced and display flash rates optimized to reduce the likelihood of visually-induced seizures. **
**Systems must provide audio cutoff for external speakers; industry standard connector for headphones and personal listening devices **
**	****(36 CFR 1193.43)**

## Examples of other S-255 requirements

**Upon request, manufacturers shall supply documentation in alternative formats at no additional charge.  (36 CFR 1193.33a)**
**Manufacturers shall identify a single point-of-contact for product information and complaint resolution.  (36 CFR 1193.33b)**
**Signal encoding and compression technologies shall not remove information needed for disability access or shall restore it upon decompression.  (36 CFR 1193.37)**
**No change shall be undertaken which decreases or has the effect of decreasing the net accessibility, usability, or compatibility of telecommunications equipment or customer premises equipment.  (36 CFR 1193.39)**

## What about Section 255 and VoIP?

**The FCC regulates communication systems.  It does *****not***** have the authority to regulate “information systems.”**
**Under current law, the Internet is treated as an information system.**
**The FCC has therefore considered Voice over Internet Protocol to be exempt from their jurisdiction.  **
**The regulatory landscape seems to be changing, motivated in part by incidents in which people with residential VoIP discovered *****during an emergency***** that they did not have access to 9-1-1 service.**
**A recommendation: Don’t achieve “compliance” with Section 255 by relying on legal loop-holes. **
**The good news: Many capabilities, of value to people with disabilities but not feasible with traditional telephony, are possible with VoIP. **
**My presentation to the FCC, asking them to remove VoIP’s S-255 exemption: **_**[http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-248634A8.pdf](http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-248634A8.pdf)**_

## Section 508, Rehabilitation Act Amendments

**GOAL:** ** Ensure that the Federal government’s electronic and information technology (E&IT) provides “comparable access” to government employees and members of the public with disabilities *****unless an undue burden would be imposed on the agency*****.  **
**PRODUCT REQUIREMENTS:****  Specific accessibility features must be present in E&IT (including telecom systems) developed, procured, maintained, or used by the government.  Conformance can be achieved through direct or compatible accessibility, and through equivalent facilitation.  (Note the difference in regulatory style: Section 508 imposes specific engineering design requirements, while the FCC’s guidelines under Section 255 say, “We expect manufacturers to find solutions for the disability access problems we’ve identified.”)**

## Code Of Federal Regulations, 36 CFR Part 1194

**The “Section 508 standards” were authored by the US Access Board and are in the Code of Federal Regulations, 36 CFR Part 1194:**
**  ****Subpart A - General Scope (1194.1)**
**  ****Subpart B - Technical Standards**
**	****- ****Software Applications and Operating Systems (1194.21)**
**	****-  Web-based Intranet and Internet Information and Applications (1194.22) **
**	****-  Telecommunications Products (1194.23)**
**	****-  Video and Multimedia Products (1194.24)**
**	****-  Self Contained, Closed Products (1194.25)**
**	****-  Desktop and Portable Computers (1194.26)**
**  ****Subpart C - Functional Performance Criteria (1194.31)**
**  ****Subpart D - Information, Documentation, and Support (1194.41) **

## Telecommunications 

**Telecommunications **
**Products**

## Section 508, Requirement 1194.23(a)

**Telecommunications products or systems which provide a function allowing voice communication and which do not themselves provide a TTY functionality shall provide a standard non-acoustic connection point for TTYs. Microphones shall be capable of being turned on and off to allow the user to intermix speech with TTY use.**
*It has been my experience that nearly all contract officers interpret the first part of this requirement to mean that analog tip/ring RJ-11 input/output ports must be available on telephony servers (e.g., PBX systems) and/or on the telephones themselves.  In many cases, the 2.5mm and 3.5mm jacks on wireless products are regarded by these officers as acceptable substitutes for the RJ-11 ports. *
*The second part of this requirement is very important: Systems must permit users to intermix speech & TTY on the same call!*

## Section 508, Requirement 1194.23(b)

**Telecommunications products which include voice communication functionality shall support all commonly used cross-manufacturer non-proprietary standard TTY signal protocols. **
*In my experience, nearly all contract officers have interpreted this to require only the US standard 45.45 baud Baudot communication protocol. Although I have been asked occasionally*** ***about TurboCode, 300 baud ASCII, and the V.18 modem protocols, it is very unusual to see an RFP that explicitly requires anything in addition to 45.45 baud Baudot.       *

## Section 508, Requirement 1194.23(c)

**Voice mail, auto-attendant, and interactive voice response telecommunications systems shall be usable by TTY users with their TTYs. **
*Every function that is available to voice users must also be accessible to TTY users *_*with their TTYs*_*.  For example, if a voice mail system allows voice users to find people in a directory, send messages, retrieve messages (including “envelope information” such as time of delivery and originator’s phone number), or automatically return someone’s phone call, the system must also permit TTY users to perform these same functions *_*with their TTYs*_*.*
*Keep in mind also that “Voice Carry Over” is a very common style of TTY operation.  This means that, even if the messaging system is prompting the user via TTY text, it must be possible for the user to leave a voice message. *
*A good idea, not required by 1194.23(c):  Systems should allow users to choose whether they wish to be prompted in voice versus TTY format, thereby making it unnecessary to provide different phone numbers to voice and TTY users.*

## Section 508, Requirement 1194.23(d)

**Voice mail, messaging, auto-attendant, and interactive voice response telecommunications systems that require a response from a user within a time interval, shall give an alert when the time interval is about to run out, and shall provide sufficient time for the user to indicate more time is required.**
*In addition to addressing the needs of people with mobility, visual, or cognitive limitations, this requirement addresses a problem faced by TTY users who rely on relay services: in the amount of time it takes for a relay operator to type a voice menu for the TTY user, and then receive & forward the response from that user, many systems will “time out” and hang up. *

## Section 508, Requirement 1194.23(e)

**Where provided, caller identification and similar telecommunications functions shall also be available for users of TTYs, and for users who cannot see displays. **
*The caller ID displays on most telephones continue to work properly when a TTY is used. The engineering challenge with our digital and VoIP phones was how to provide caller ID and related info for users who cannot see displays.  *
*I am asked frequently whether residential voice-output caller ID adjuncts can be used in conjunction with our digital and VoIP telephones.  Although the answer is yes, I often advise against this approach because of the additional expense, and because it does not provide a solution for 1194.23(k)(4).*
*I am asked frequently about refreshable Braille displays.  Unfortunately, only a small proportion of people who are blind or visually impaired are able to read Braille.  For this reason, in most cases, I have felt that provision of caller ID and phone status information by voice is the preferred approach.*
*The solution we implemented is described later in this presentation...  *

## Section 508, Requirement 1194.23(f)

**For transmitted voice signals, telecommunications products shall provide a gain adjustable up to a minimum of 20 dB. For incremental volume control, at least one intermediate step of 12 dB of gain shall be provided. **
*There are conditions under which a 20+ dB amplitude boost could conflict with other Federal regulations, notably the OSHA limit on the maximum sound pressure level permitted for transducers held against the ear. *
*Do not misinterpret 1194.23(f): It does not require sound levels that could be unsafe! *
*In the VPATs (“Voluntary Product Accessibility Template”) that I have prepared for Avaya products, I state that we comply with this requirement, stopping at the point where the resulting amplitude would exceed OSHA limits.  I have never been told by a contract officer that this response is unsatisfactory.*

## Section 508, Requirement 1194.23(g)

**If a telecommunications product allows a user to adjust the receive volume, a function shall be provided to automatically reset the volume to the default level after every use.**
*This is a safety net, given that the 20 dB gain required by 1194.23(f) could be uncomfortable others who use the phone subsequently.*

## Section 508, Requirement 1194.23(h)

**Where a telecommunications product delivers output by an audio transducer which is normally held up to the ear, a means for effective magnetic wireless coupling to hearing technologies shall be provided. **
*This requirement may seem like a restatement of regulations that are already enforced by the FCC.  Not true!*
*The headsets that may be used in conjunction with telecom equipment are not regulated by the FCC.  One purpose of 1194.23(h) is to ensure that the headsets (and handsets) acquired by the government provide effective magnetic coupling.  *
*Note also that not all wireless devices provide effective magnetic coupling.*
*Most headsets and wireless devices that satisfy this requirement will be described as “hearing aid compatible.”*

## Section 508, Requirement 1194.23(i)

**Interference to hearing technologies (including hearing aids, cochlear implants, and assistive listening devices) shall be reduced to the lowest possible level that allows a user of hearing technologies to utilize the telecommunications product. **
*The interference problem addressed by this requirement is seen most frequently in wireless devices, which can generate electro-magnetic pulses at audible frequencies.*** **
*This requirement has been criticized because, in the absence of specific metrics, there is no way to assess whether a product complies. Metrics were omitted because there is an expectation that there will be significant, steady improvements in the techniques for electro-magnetic coupling and shielding.  (For those who desire quantitative metrics, it is generally felt that the ANSI/IEEE C63.19 Standard represents a reasonable test.)*

## Section 508, Requirement 1194.23(j)

**Products that transmit or conduct information or communication, shall pass through cross-manufacturer, non-proprietary, industry-standard codes, translation protocols, formats or other information necessary to provide the information or communication in a usable format. Technologies which use encoding, signal compression, format transformation, or similar techniques shall not remove information needed for access or shall restore it upon delivery. **
*Basically an extension of 1194.23(b), intended to include functions such as closed-captioning when it’s provided as an adjunct to a video teleconference.  Note with regard to wireless and VoIP telephony, it’s okay to encode the TTY tones for transmission if the tones and/or corresponding text are reconstructed accurately at the far end, assuming that the implementation does not preclude mixed-mode voice and TTY communication.**  *

## Section 508, Requirement 1194.23(k)(1)

**Products which have mechanically operated controls or keys shall comply with the following: **
**Controls and keys shall be tactilely discernible without activating the controls or keys.**
*This requirement addresses touch-screens and touch-activated controls.  Although these input devices are not prohibited, the locations of the controls and keys cannot be discernible solely by vision. *
*This requirement calls for keys to be tactilely discernible.  This means that users must be able to tell, by touch, that a key is present.  Note that the requirement does not call for the keys to be tactilely identifiable.  There is a big difference!  *
*There are requirements elsewhere, such as 1193.41(a) and 1194.31(a), that address the problem of control identification.  Most telephones (not all) facilitate tactile navigation of the dial pad by arranging the keys in a standard 3X4 matrix, with a raised nib on the 5 key.  Unfortunately, the location and shape of the other controls and keys has not been standardized, and are not always designed with tactile identification in mind.*

## Section 508, Requirement 1194.23(k)(2)

**Products which have mechanically operated controls or keys shall comply with the following: **
**Controls and keys shall be operable with one hand and shall not require tight grasping, pinching, twisting of the wrist. The force required to activate controls and keys shall be 5 lbs. (22.2N) maximum. **
*Several physical conditions can reduce a person’s ability to operate controls and keys.  Some examples: tremor, an inability to use both hands simultaneously, poor fine-motor control, partial or complete paralysis, muscle weakness, and reliance on prosthetic devices. *
*It is unusual to see a telephone that fails to comply with this requirement.  *
*Note that 1194.25 (Self Contained, Closed Products) and 1194.26 (Desktop and Portable Computers) explicitly require compliance with 1194.23(k)(1-4).  *

## Section 508, Requirement 1194.23(k)(3)

**Products which have mechanically operated controls or keys shall comply with the following: **
**If key repeat is supported, the delay before repeat shall be adjustable to at least 2 seconds. Key repeat rate shall be adjustable to 2 seconds per character. **
*It is unusual to see a telephone that fails to comply with this requirement – chiefly because “key repeat” is not a function that one commonly finds in telephones.  *
*Note that 1194.25 (Self Contained, Closed Products) and 1194.26 (Desktop and Portable Computers) explicitly require compliance with 1194.23(k)(1-4).  *

## Section 508, Requirement 1194.23(k)(4)

**Products which have mechanically operated controls or keys shall comply with the following: **
**The status of all locking or toggle controls or keys shall be visually discernible, and discernible either through touch or sound.**
*A typical modern business telephone has an LCD screen on which a large amount of information is presented visually.  Examples include caller ID, which lines are in use, which lines are on hold, whether there is new voicemail, whether the phone is forwarded, whether “do not disturb” is active, and whether a caller on hold has disconnected.  Job-specific information may also be displayed.  For example, when used in contact centers, the phones will display information such as number of calls in queue, mean waiting time, and split assignment.  (In some Avaya configurations, the status of over 240 different functions may be displayed!) *
*For people who are visually impaired, the inability to access the same information as sighted people can be a significant inconvenience.  More importantly, it can be an insurmountable barrier to communication-centric jobs that might otherwise be ideal for people with disabilities, such as receptionist or contact center agent.*

## Section 508, Requirement 1194.31(e)

**At least one mode of operation and information retrieval that does not require user speech shall be provided, or support for assistive technology used by people with disabilities shall be provided. **
*This requirement is one of six within Subpart C, the Functional Performance Criteria.  It is mentioned here because technologies such as automatic speech recognition and automatic speaker identification are regarded by many as a panacea for people with disabilities.*
*These technologies can improve accessibility for some people, but harm it for others (such as people who are unable to speak clearly).  *
*It’s okay to have functions be available via speech input.  It’s okay to have functions that are not available via speech input.  What’s *_*not*_* okay is to have functions that are available solely by speech.*

## Description and Demonstration of Accessible Solutions 

**Description and Demonstration of Accessible Solutions**** **

## A closer look at two products

**TTY Messaging**
**Universal Access Phone Status**
**In both cases, we did the following:**
**Identify the users’ needs.**
**Identify capabilities that already existed within the “plain vanilla” versions of the products, that we could leverage in order to build the accessibility adjuncts.**
**Because we were able to piggyback onto other solutions that already existed, *****we have been able to provide these accessibility adjuncts for free.***

## TTY messaging

**Problem: If someone calls you, and you don’t answer your phone, the call gets forwarded to *****voice*****mail.  What if it’s a TTY user?**
**Users’ needs: Callers must be able to choose whether they wish to be prompted by voice or in TTY format.  Regardless of the prompting style they choose, they must be able to leave a voice or TTY message.**
**Key capabilities that already existed: (1) The ability to let callers choose the *****spoken *****language for prompting; (2) the ability to record and play back TTY tones reliably. **
**The solution: Create a TTY “announcement set” in exactly the same way that spoken announcement sets are created, i.e., by generating audio recordings of the prompts and menus that must be presented to users. **

## Universal Access Phone Status

**Problem: Business phones use LCDs and LEDs to provide info.**
**Users’ needs: People with visual impairments cannot get important info, such as caller ID, whether the phone is forwarded, which lines are in use, and whether someone on hold has disconnected.**
**Key capabilities that already existed: (1) The telephone’s display is controlled by the telephony server (e.g., the PBX); (2) it’s possible to discover what’s being shown on a phone’s display via a secure login into the server; (3) specific *****changes***** that occur in a telephone’s display can only mean one thing.  For example:**
**On Model 6416 phones, only one thing can cause the green LED next to button #1 to go from steady-on to flashing: “Line 1 is on hold.”  **
**Only one thing can cause that LED to go from flashing to off: “The party on line 1 has disconnected.”**
**The solution: PC-based software that can**
**Monitor the display-controlling status table that is maintained by the PBX, and describe *****by voice***** what the display is indicating.**
**Immediately detect *****changes *****that occur in the status table, and describe *****by voice *****what those changes mean.**
**Allow users to choose what should be voiced-out and when.**

## A free prize in every box!

**Even though the Section 508 rules encourage Federal agencies to purchase products that support accessibility, many of the agencies have failed to activate or use the features that have been provided.**
**If you have an Avaya Communication Manager system, release 2.3 or higher, and any recent Avaya digital or IP telephone, you have everything you need in order to use Universal Access Phone Status.  The software can be downloaded *****for free***** from:**
- _[http://support.avaya.com/japple/css/japple?PAGE=ProductArea&temp.productID=276960](http://support.avaya.com/japple/css/japple?PAGE=ProductArea&temp.productID=276960)_
**If you have an Avaya Intuity AUDIX, Release 5 or higher, or an Avaya Modular Messaging System, Release 3 or higher, you already have support for TTY users, including VCO and HCO.  There is no license fee or right-to-use fee.  Here’s the catch: your system administrator needs to turn it on.**** **