0x2755 Low Layer Compatibility Layer 1 Info
(Interworking Only)

Used in:
0x0033 NPDI Universal ICB

Byte | Description
0, 1 | Tag 0x2755
2, 3 | Length Variable
4, 5 | Value[0] User information layer 1 protocol 0x01 CCITT standardized rate adaption V.110 [7] and X.30 [8]. 0x02 Recommendation G.711 [10] Mu Law 0x03 Recommendation G.711 A-law 0x04 Recommendation G.721 [11] 32 K bits/s ADPCM and recommendation I.460 [15] 0x05 Recommendations H.221 and H.242 0x07 Non CCITT standardized rate adaption. 0x08 CCITT standardized rate adaption V.120 [9]. 0x09 CCITT standardized rate adaption X.31 [14] HDLC flag stuffing. All the other values are reserved.
| Value[1] User Rate 0x00 Rate is indicated by E bits specified in Recommendation I.460 or may be negotiated in-band. 0x01 0.6 k bits/s Recommendations V.6 [16] and X.1 [17] 0x02 1.2 k bits/s Recommendation V.6 0x03 2.4 k bits/s Recommendations V.6 and X.1 0x04 3.6 k bits/s Recommendation V.6 0x05 4.8 k bits/s Recommendations V.6 and X.1 0x06 7.2 k bits/s Recommendation V.6 0x07 8 k bits/s Recommendations I.460 0x08 9.6 k bits/s Recommendations V.6 and X.1 0x09 14.4 k bits/s Recommendation V.6 0x0a 16 k bits/s Recommendations I.460 0x0b 19.2 k bits/s Recommendation V.6 0x0c 32 k bits/s Recommendations I.460 0x0e 48 k bits/s Recommendations V.6 and X.1 0x0f 56 k bits/s Recommendation V.6 0x10 64 k bits/s Recommendation X.1 0x15 0.1345 k bits/s Recommendation X.1 0x16 0.100 k bits/s Recommendation X.1 0x17 0.075/ 1.2 k bits/s Recommendations V.6 & X.1 0x18 1.2/0.075 k bits/s Recommendations V.6 & X.1 0x19 0.050 k bits/s Recommendations V.6 & X.1 0x1a 0.075 k bits/s Recommendations V.6 & X.1 0x1b 0.110 k bits/s Recommendations V.6 & X.1 0x1c 0.150 k bits/s Recommendations V.6 & X.1 0x1d 0.200 k bits/s Recommendations V.6 & X.1 0x1e 0.300 k bits/s Recommendations V.6 & X.1 0x1f 12 k bits/s Recommendations V.6 All the other values are reserved.
| Value[2] Intermediate Rate 0x00 Not used 0x01 8 k bits/s 0x02 16 k bits/s 0x03 32 k bits/s All the other values are reserved.
| Value[3] Physical properties Negotiation Indicator: 0 In-band negotiation not possible. 1 In-band negotiation possible. Network Independent Clock (NIC) on Transmit: 0 Not required to send data with network independent. 1 Required to send data with network independent clock. Network Independent Clock (NIC) on Receive: 0 Cannot accept data with network independent clock (sender does not support this optional procedure). 1 Can accept data with network independent clock (sender does support this optional procedure). Flow Control on Transmit: 0 Not required to send data with flow control mechanism. 1 Required to send data with flow control mechanism. Flow control on Receive: 0 Cannot accept data with flow control mechanism (sender does not support this optional procedure). 1 Can accept data with flow control mechanism (sender does support this optional procedure). Header / No Header: This provides rate adaption header/ no header information. 0 Rate adaption header not included. 1 Rate adaption header included. Multiple Frame establishment support in data link: 0 Multiple frame establishments not supported. Only UI frames allowed. 1 Multiple frame establishments supported.
| Value[4] Physical Mode Synchronous/ Asynchronous: 0 Synchronous data. 1 Asynchronous data. Mode of operation: 0 Bit transparent mode of operation. 1 Protocol sensitive mode of operation. Logical Link Identifier Negotiation: 0 Default LLI=256 only. 1 Full protocol negotiation. Assignor/ Assignee: 0 Message originator is "default assignee". 1 Message originator is "assignor only". In-band negotiation: 0 Negotiation is done with user information messages on a temporary signaling connection. 1 Negotiation is done in-band using logical link zero. Duplex Mode: 0 Half Duplex. 1 Full Duplex.
| Value[5] Number of stop bits 0x00 Not used 0x01 1 bit 0x02 1.5 bits 0x03 2 bits All the other values are reserved.
| Value[6] Number of data bits 0x00 Not used 0x01 5 bit 0x02 7 bits 0x03 8 bits All the other values are reserved.
| Value[7] Parity 0x00 Odd 0x02 Even 0x03 None 0x04 Forced to 0 0x05 Forced to 1 All the other values are reserved.

Network Protocol Data Intelligence. Also called “Interworking,” it is a software product that operates within Excel’s Call Control (Layer 4) and Services (Layer 5) call processing layers. NPDI is meant to enhance Excel’s call processing product offering by allowing call processing layers (specifically Layers 4 and 5) to perform advanced analysis, generation, and conversion of Network Signaling (NS) Layer 3 information.
See Information Control Block.
Comité Consultatif Internationale de Telephonique et Telegraphique (now ITU)
Network Interface Card
A group of data bits in a specific format, with a flag at each end to indicate the beginning and the end of the frame.