Lucent Technologies DEFINITY Enterprise Communications Server Release 5, CallVisor, ASAI Protocol Reference Instructions Manual

							Message Type Information Element
Issue 6  June 1997
4-5
Thus, both endpoints may assign an identical value and the CRV flag prevents a 
collision in their use.
Although permitted, it is recommended that adjuncts do not initiate associations 
with CRVs in the range 1 to 32, inclusive. Rather, an adjunct might start assigning 
CRVs with the highest possible values and work downwards, or begin assigning 
CRVs at 33 and work upwards.
Message Type Information Element
The message type identifies the function of the message being sent. It is the third 
part of every message and may be one or two bytes long. The MIM is the only 
multi-byte message type used by the ASAI. Table 4-1 shows the single-byte 
message-type codings. Table 4-2 shows the two-byte message type codings.
Table 4-1. Single-Byte ASAI Message Types
87654321
0 Message type Byte 1
0 1 0 1 1 0 1 0 RELease COMplete
01100010 FACility
01100100 REGister
01000110 RESTart
01001110 RESTart ACKnowledge
01111101 STATUS
Table 4-2. Two-Byte ASAI Message Types
8 7 6 5 4 3 2 1  8 7 6 5 4 3 2 1
0 0 0 0 0 0 0 0 1 - - - - - - - Network Specific Message
1 1 1 0 1 1 1 Management Information (MIM) 
						

							Information Elements
4-6Issue 6  June 1997 
Codeset Information Elements
Coding Rules
Information element coding follows the rules below.
Two categories of information elements are defined:
nSingle-byte information elements (see Figure 4-3 [a] Single-byte 
information element format)
nVariable length information elements (see Figure 4-3 [b] Variable length 
information element format)
Figure 4-3. Formats of Information Elements
Table 4-3 summarizes the coding of the information element identifier bits.
There is an order of appearance for information elements within a message or 
enveloping FIE. All IEs from any given code set are grouped together. Within the 
code set grouping, the code values of the information element identifier determine 
the order of appearance of the variable length information elements within a 
message. These IEs appear in ascending numerical order. Thus, within a 
message, the information elements from a given code set (for example, 0 and 6) 
must be presented in the order of increasing byte code identifier. This allows the 
receiving equipment to detect the presence or absence of a particular information 
element without scanning through an entire message.8 7654321
1Information
element
identifierContents of
information
elementsByte 1
(a) Single-byte information element format
87654321
0 Information element identifier Byte 1
Length of contents of information element (bytes) 2
Contents of information element 3
(b) Variable length information element formatetc. 
						

							Codeset Information Elements
Issue 6  June 1997
4-7
Where the description of information elements in this specification contains spare 
bits, these bits are indicated as being set to “0.” To allow compatibility with future 
implementations, messages should not be rejected simply because a spare bit is 
set to “1.”
The second byte of a variable length information element indicates the total length 
of the contents of the remainder of that information element. It is the binary coding 
of the number of remaining bytes, with bit 1 as the least significant bit (2°×).
The following set of terms is used in the figures depicting the structure of variable 
length information elements:
a. The first digit in the byte number column to the right of the figure identifies 
one byte or a group of bytes.
b. Each byte group is a self-contained entity. The internal structure of a byte 
group may be defined in alternative ways.
c. A byte group is formed by using some extension mechanism. The preferred 
extension mechanism is to extend a byte (N) through the next byte(s) (Na, 
Nb, etc.) by using bit 8 in each byte as an extension bit. The bit value “0” 
indicates that the byte continues through the next byte. The bit value “1” 
indicates that this byte is the last byte. If byte (Nb) is present, the preceding 
bytes (N and Na) must also be present.
In the format descriptions for the information elements, bit 8 is marked “0/1 
ext” if another byte follows. Bit 8 is marked “1 ext” if this is the last byte in 
the extension domain.
d. In addition to the extension mechanism defined above, a byte (N) may be 
extended through the next byte(s) (N.1, N.2, and so on) by indications in 
bits 1 (of byte N).
e. The mechanisms in “c” and “d” may be combined.
f. Optional bytes are marked with asterisks (*).  
						

							Information Elements
4-8Issue 6  June 1997 
Table 4-3. Information Element Identifier Coding
87654321
1 : : ---- Single-byte information elements:
 0
0 :::::::  Variable length information elements:
 Codeset 0
 0001000
 Cause
 0001100 Connected number
 0010000 Call identity
 0010100 Call state
 0011110 Progress Indicator
 0101001 Date/time
 1101100 Calling party number
 1110000  Called party number
 1110100  Redirecting number
 1  110110 Redirection number
 1111001 Restart indicator
 111 1110 User-User Information
         Codeset 6
0000001
 Originating Line Information
 0000010 User Entered code
 0000011 Resource Status
 00 01010 Trunk Identification
 0001011 Trunk group/trunk status
 0010111 Old Party Identifier
 0011011 Version
 0011100 Facility
 1000100 Party id
 1000110 Counter
 1000111 Specific event
 1001000 Feature
 1001001 Domain
 1001010 Conf/Trans options
 1001011 Call options
 1001101 Item
 1001110 Service Circuit
 1001111 Status
 1010001 Resource identifier
 1010010 Data Item
 1010011 Data Bit Map
 1010110 Generic Billing
 1111010 Management Information (MIE)
 1111011 Lookahead Interflow 
						

							Codeset Information Elements
Issue 6  June 1997
4-9
One common value in the single-byte format is employed in each code set to shift 
from one code set to another. The contents of this shift item identify the code set 
to be used for the following information element(s). The code set in use at any 
given time is referred to as the active code set. By convention, code set 0 is the 
initially active code set. Codeset 6 is used for Lucent Technologies-specific 
supplementary service information elements, including ASAI information 
elements. The FIE transports ASAI information across the ECS/adjunct interface. 
The ECS ASAI does not use codesets 1, 2, 3, 4, 5, or 7.
The ASAI supports a locking shift to code set 6. The locking shift must follow the 
last information element in code set 0. One or more variable length information 
elements from code set 6 follow the locking shift.
Locking Shift Procedure
The locking shift procedure uses an information element to indicate the new active 
code set. For example:
Code set 0 is active at the start of message content analysis. If a locking shift to 
code set 6 is encountered, information elements in the message are interpreted 
according to the information element identifiers assigned in code set 6.
NOTE:
The FIE (which is a codeset 6 IE) contains a sequence of IEs within it. 
Interpretation of the IEs inside of the FIE begins in codeset 0 and shifts to 
codeset 6 if a lock shift is encountered within the FIE.
The locking shift to code set 6 must be present in a message when information 
elements from code set 6 are included in the message. 
						

							Information Elements
4-10Issue 6  June 1997 
Figure 4-4 shows the single-byte information for the locking shift.
Figure 4-4. Locking Shift to Codeset 68 7654321
Shift Codeset 6
1 0010110Byte1
identification
   
0 in bit position 4
    indicates locking shift 
						

							Codeset 0 Information Elements
Issue 6  June 1997
4-11
Codeset 0 Information Elements
The codeset 0 information elements are CCITT-approved and are incorporated in 
the CCITT specification. The ASAI codeset 0 IEs drawn from this specification are 
as follows:
Call State
The Call State information element shown in Figure 4-5 displays the state of a 
CRV and is present in the BRI STATUS message. Since certain ASAI endpoints 
might transmit a BRI STATUS message to the ECS when the endpoint encounters 
a protocol error, the Call State information element is included in this document. 
The ECS does not support its use in any ASAI capability messaging.
.
Figure 4-5. Call State Information Element Call State Date/Time
Called Party Number Progress Indicator
Calling Party Number Redirecting Number
Cause Redirection Number
Call Identity Restart Indicator
Connected Number User to User Information
8 7654321
Call State
00010100Byte1
information element identifier
Length of Called Party Number Information Element 2
01100001 3
CRV State
Value Call State
0 0 0 0 0 0 0 0Null — CRV not in use
0 0 0 0 1 0 1 0 Active — CRV in use 
						

							Information Elements
4-12Issue 6  June 1997 
Called Party Number
The Called Party Number IE shown in Figure 4-6 identifies the destination of a 
call.
Figure 4-6. Called Party Number Information Element8 7654321
Called Party Number
0 1110000 Byte1
information element identifier
Length of Called Party Number Information Element 2
1
Ext 3
Type of Address Numbering Plan
0
SpareAddress Digits 4
etc.
Extension Bit0: description extends into next byte
1: last byte of the description element
Type ofBits
Address765
000 unknown
0 0 1 international
010 national
1 0 0 subscriber
NumberingBits
Plan4321
0000 unknown
0001 ISDN/telephony numbering plan
0010 reserved
1001 private numbering plan 
						

							Codeset 0 Information Elements
Issue 6  June 1997
4-13
The ECS permits a maximum of 31 address digits and sends/receives only those 
ASCII characters shown above. Any adjunct must:
a. Accept all characters shown.
b. Not send characters other than those shown. Doing so results in the ECS 
denying (return error) the request.
There may be instances of event reports where an address for the called party is 
not available to the ECS. In such cases, the Called Party Number IE is present in 
the event reports where ASAI requires it as a mandatory event report item. 
However, in such a case, the Address field of the IE is not present; the length of 
the resulting IE is one (1); the Type of Address and Numbering Plan fields are 
present. Any adjunct interfacing to the ECS should be prepared to receive the 
Called Party Number IE in this format.
The adjunct should also be prepared to accept the default called party number 
values “#####,” or “*****.” Address DigitsBits Address Digit
7 654321 value
0 110000 0
0 110001 1
0 110010 2
0 110011 3
0 110100 4
0 110101 5
0 110110 6
0 110111 7
0 111000 8
0 111001 9
0 100011 #
0 101010 * 
						

							Information Elements
4-14Issue 6  June 1997 
Calling Party Number
The Calling Party Number IE shown in Figure 4-7 identifies the origin of a call.
Figure 4-7. Calling Party Number8 7654321
CallingParty Number
0 1101100 Byte1
information element identifier
Length of Calling Party Number Information Element 2
1
Ext 3
Type of Address Numbering Plan
0
SpareAddress Digits 4
etc.
Extension Bit0: description extends into next byte
1: last byte of the description element
Type ofBits
Address765
000 unknown
0 0 1 international
0 1 0 national
100 subscribe
The ECS does not include the optional PRI byte for 
the presentation indicator and screen indicator
NumberingBits
Plan4321
0000 unknown
0001 ISDN/telephony numbering plan
0010 reserved
1001 private numbering plan