Download 10209144R1 - Telecommunications Industry Association

Telecommunications Industry Association
TR30.1/02-09-144
(TIA)
McLean, VA, September 9th – 12th, 2002
COMMITTEE CONTRIBUTION
Technical Committee TR-30 Meetings
SOURCE:
Conexant Systems
CONTACT:
Frank Chen
Phone:
+1 (949) 579-3296
Fax:
+1 (949) 579-3667
Email: [email protected]
TITLE:
Synchronous Data Type in V.moip
PROJECT:
PN-0012
DISTRIBUTION:
Members of TR-30.1
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ABSTRACT
This contribution discusses Synchronous Data Type in V.MoIP.
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and conditions for purpose of practicing a TIA Publication incorporates this contribution.
This document has been prepared by the Source Company(s) to assist the TIA Engineering Committee. It is proposed to the
Committee as a basis for discussion and is not to be construed as a binding proposal on the Source Company(s). The Source
Company(s) specifically reserves the right to amend or modify the material contained herein and nothing herein shall be
construed as conferring or offering licenses or rights with respect to any intellectual property of the Source Company(s) other
than provided in the copyright statement above.
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1.
Introduction
This contribution discusses Synchronous Data Type in V.moip.
2.
Synchronous Data Type
For MoIP symmetric non-error correcting connection scenario, if a gateway determines this is a
HDLC frame based synchronous connection, it may transmit data with this type over IP
network. With this data type, HDLC frames, including CRC, are sent over IP network. The
HDLC flags/abort and “0” bit stuffing are removed and not sent over IP.
The support of this data type is optional. A gateway may indicate the capability of supporting
this data type. A gateway may optionally use this data type to transmit data when both gateways
indicate the capability of supporting this data type. The gateway that receives synchronous data
type packet from IP network shall regenerate HDLC frame on PSTN link by adding HDLC
flags/abort and “0” bit stuffing.
How a gateway determines it has synchronous connection is beyond the scope of v.moip.
3.
Synchronous Data Format
The format of this data type message is given in the following figure.
r msgID
R
st
octets
Figure 1 – Synchronous data type message format
In this message:
r
is a 1 bit field reserved for future use by the ITU-T. Message senders
shall set this field to 0. Message receivers shall ignore the value of this
field.
msgID
is a 7 bit field whose value identifies the message; a unique value is
assigned to the synchronous data type.
R
is a 6 bit field reserved for future use by the ITU-T. Message senders
SYNCHRONOUS DATA TYPE IN V.MOIP
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shall set this field to 0. Message receivers shall ignore the value of this
field.
St
is 2 bits field indicating synchronous data frame state: 0 – data frame
without termination; 1 – data frame with flag termination; 2 – data
frame with abort termination
Octets
Is integral number of octets representing the body of synchronous data
frame
Each message consists of the r field, the message ID field, R field, Sync state field, and Octets
field. The r field and message ID field together comprise one octet. The R field and Sync State
field comprise one octet. Octets field contains an integral number of octets.
If the message contains HDLC frame data that reaches the end of frame with flag, sync state
field shall be set to 1. If the message contains HDLC frame data that reaches frame abort, sync
state field shall be set to 2. If the message contains HDLC frame data that does not reach either
frame flag or frame abort, sync state field shall be set to 0.
4.
Summary
It is proposed that the committee agrees to the following:
A
Agreed
v.moip supports synchronous data type defined in this
contribution as an optional data type.
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SYNCHRONOUS DATA TYPE IN V.MOIP
10209-144