The document to which this cover statement is attached is submitted to a Formulating Group or sub-element thereof of the Telecommunications Industry Association (TIA) in accordance with the provisions of Sections 6.4.1–6.4.6 inclusive of the TIA Engineering Manual dated March 2005, all of which provisions are hereby incorporated by reference.
We have some concerns about some of the proposals to change the draft of TIA-1063 in TR41.1.1/05-08-003, “Modification to some clauses and subclauses of TR41.1.1 draft document”.
Item 3 / TR41.1.1/05-08-003: Disconnect Signal
States: “Section 220.127.116.11 describes a disconnect signal that is sent by the ATA. For clarity, it needs to be defined what it is.”
Proposes: “Add – Analog Telephone adapter disconnect signal appears as no DC voltage (no loop current) between tip and ring for a period of at least 600 ms.”
However, when looking at Section 18.104.22.168, we find:
It is desirable that the analog telephone port transmits a disconnect signal as described in 22.214.171.124 toward the analog telephony equipment within 2 minutes after detection of a permanent or partial-dial time-out at the analog telephone port.
And when following up the reference at Section 126.96.36.199, we find:
The analog telephone port shall remove dial tone within 500 ms after receiving the start of the first DTMF digit.
So actually, Section 188.8.131.52 does not describe a disconnect signal at all.
Probably what was intended is Section 184.108.40.206, which defines a disconnect signal.
If flash signals generated by the analog telephony equipment are not used by the terminal adapter to initiate internal calling features, the terminal adapter shall interpret on-hook intervals of 1500 ms or greater as valid disconnect signals.
Correct the reference in Section 220.127.116.11 from “18.104.22.168” to “22.214.171.124”;
Do not accept the change from 1500 ms to 600 ms.
Item 4 / TR41.1.1/05-08-003: On-hook Interval
States: “Section 126.96.36.199 has the ambiguity of on-hook time interval between 150 ms to 300 ms. This period should either be included on the ignore side (item 1) OR itemize the period as reserved for future use.”
Proposes: “In Section 188.8.131.52, add another subheading between 1 and 2 as ‘Reserved on-hook intervals of 150 ms to 300 ms for future use.’”
However, when looking at Section 184.108.40.206, we find:
220.127.116.11 If flash signals generated by the analog telephony equipment are used by the terminal adapter to initiate internal calling features, the terminal adapter shall:
(1) Ignore on-hook intervals of 150 ms or less.
(2) Interpret on-hook intervals of 300 ms to 1.1 second as valid flash signals.
(3) Interpret on-hook intervals of 1.5 seconds or greater as valid disconnect signals.
The proposal of -003 is to introduce a 4th state for the on-hook interval between 150 ms and 300 ms, for future use.
We have two objections to this proposal:
Isn’t it important to include some margin for implementation? Just as there is between the 1.1- and the 1.5-second gap?
Could there be unintended implications for higher-layer applications from changing the protocol in this way?
Our proposal: Do not change the interpretation of the on-hook interval.