Figure 26/Q.763 - CCITT 73380 The following codes are used in the optional backward call indicators parameter field: bit A: In-band information indicator 0 no indication 1 in-band information or an appropriate pattern is now available bit B: Call forwarding may occur indicator 0 no indication 1 call forwarding may occur bits C-D: Spare bits E-H: Reserved for national use 3.25 Optional forward call indicators The format of the optional forward call indicators parameter field is shown in Figure 27/Q.763. Figure 27/Q.763 - CCITT 73380 The following codes are used in the optional forward call indicators parameter field: bits B A: Closed user group call indicator 0 0 non-CUG call 0 1 spare 1 0 closed user group call, outgoing access allowed 1 1 closed user group call, outgoing access not allowed bit C-H: Spare 3.26 Original called number The format of the original called number parameter field corresponds to the format shown in Figure 28/Q.763. The following codes are used in the subfields of the original called number parameter field: a) Odd/even indicator: see S 3.7 a) b) Nature of address indicator: see S 3.7 b) c) Numbering plan indicator: see S 3.7 d) d) Address presentation restricted indicator: see S 3.8 e) e) Address signal: see S 3.8 g) f) Filler: see S 3.7 h). Figure 28/Q.763 - T1110060-88 3.27 Range and status The format of the range and status parameter field is shown in Figure 29/Q.763. Figure 29/Q.763 - CCITT 73360 The following codes are used in the subfields of the range and status parameter field: a) Range A number in pure binary representation ranging from 0 to 255. Range code 0 indicates absence of the status field. The number represented by a non-zero range code +1 indicates the range of circuits affected by the message. b) Status PAGE26 Fascicle VI.8 - Rec. Q.763 The status subfield contains from 1 to 256 status bits numbered from 0 to 255. Status bit 0 is located in bit position 1 of the first status subfield octet. Other status bits follow in numerical order. The number of relevant status bits in a given status subfield is equal to range +1. Each status bit is associated with a circuit identification code such that status bit n is associated with circuit identification code m+n, where m is the circuit identification code contained in the message. Fascicle VI.8 - Rec. Q.763 PAGE49 The status bits are coded as follows: - in circuit group blocking messages 0 no indication 1 blocking - in circuit group blocking acknowledgement messages 0 no indication 1 blocking acknowledgement - in circuit group unblocking messages 0 no indication 1 unblocking - in circuit group unblocking acknowledgement messages 0 no indication 1 unblocking acknowledgement - in circuit group reset acknowledgement messages 0 not blocked for maintenance reasons 1 blocked for maintenance reasons The number of circuits affected by a group supervision message is limited to 32 or less. For the group reset and query messages this requires that the range value be 31 or less. For the group blocking and unblocking messages the range value may be up to 255, but the number of status bits set to 1 must be 32 or less. For the group blocking, unblocking and reset messages, range code 0 is reserved. 3.28 Redirecting number The format of the redirecting number parameter field corresponds to the format shown in Figure 28/Q.763. The following codes are used in the subfields of the redirecting number parameter field: a) Odd/even indicator: see S 3.7 a) b) Nature of address indicator: see S 3.7 b) c) Numbering plan indicator: see S 3.7 d) d) Address presentation restricted indicator: see S 3.8 e) e) Address signal: see S 3.8 g) f) Filler: see S 3.7 f). 3.29 Redirection information The format of the redirection information parameter field is shown in Figure 30/Q.763. Figure 30/Q.763 - CCITT 73375 PAGE26 Fascicle VI.8 - Rec. Q.763 The following codes are used in the redirection information parameter field: bits C B A: Redirecting indicator 0 0 0 no redirection 0 0 1 call rerouted 0 1 0 call rerouted, all redirection information presentation restricted 0 1 1 call forwarded 1 0 0 call forwarded, all redirection information presentation restricted 1 0 1 call rerouted, redirection number presentation restricted 1 1 0 call forwarded, redirection number presentation restricted 1 1 1 spare bit D: Spare bits H G F E: Original redirection reasons 0 0 0 0 unknown/not available 0 0 0 1 user busy 0 0 1 0 no reply 0 0 1 1 unconditional 0 1 0 0 to spare 1 1 1 1 bits K J I: Redirection counter. Number of redirections the call has undergone expressed as a binary number between 1 and 5. bit L: Spare bits P O N M: Redirecting reason 0 0 0 0 unknown/not available 0 0 0 1 user busy 0 0 1 0 no reply 0 0 1 1 unconditional 0 1 0 0 to spare 1 1 1 1 3.30 Redirection number The format of the redirection number parameter field corresponds to the format shown in Figure 9/Q.763. The following codes are used in the subfields of the redirection number parameter field: a) Odd/even indicator: see S 3.7 a) b) Nature of address indicator: see S 3.7 b) c) Internal nerwork number indicator: see S 3.7 c) Fascicle VI.8 - Rec. Q.763 PAGE49 d) Numbering plan indicator: see S 3.7 d) e) Address signal: see S 3.8 f) f) Filler: see S 3.7 f). 3.31 Signalling point code (national use) The format of the signalling point code parameter field is shown in Figure 31/Q.763. Figure 31/Q.763 - CCITT 85270 The signalling point code is a pure binary representation of the code allocated to a node in the signalling network. 3.32 Subsequent number The format of the subsequent number parameter field is shown in Figure 32/Q.763. Figure 32/Q.763 - CCITT 73331 The following codes are used in the subfields of the subsequent number parameter field: a) Odd/even indicator: see S 3.7 a) b) Address signal: see S 3.7 e) c) Filler: see S 3.7 f). 3.33 Suspend/resume indicators The format of the suspend/resume indicators parameter field is shown in Figure 33/Q.763. Figure 33/Q.763 - CCITT 73370 The following codes are used in the suspend/resume indicators parameter field: bit A: Suspend/resume indicator 0: ISDN subscriber initiated 1: network initiated bits B-H: Spare PAGE26 Fascicle VI.8 - Rec. Q.763 3.34 Transit network selection (national use) The format of the transit network selection parameter field is shown in Figure 34/Q.763. Figure 34/Q.763 - T1110120-88 The following codes are used in the subfields of the transit network selection parameter field: a) Odd/even indicator 0 even number of digits 1 odd number of digits b) Type of network identification 000 CCITT-standardized identification 010 national network identification other reserved c) Network identification plan i) For CCITT-standardized identification 0000 unknown 0011 public data network identification code (DNIC), Recommendation X.121 0110 public land mobile network identification code (MNIC), Recommendation E.212 other spare ii) For national network identification This information is coded according to national specifications. d) Network identification This information is organized according to the network identification plan and the encoding principles given in S 3.8 f). 3.35 Transmission medium requirement The format of the transmission medium requirement parameter field is shown in Figure 35/Q.763. Figure 35/Q.763 - CCITT 73380 The following codes are used in the transmission medium requirement parameter field. 00000000 speech 00000001 spare 00000010 64 kbit/s unrestricted 00000011 3.1 kHz audio 00000100 alternate speech (service 2)/64 kbit/s unrestricted (service 1) (Note 1) 00000101 alternate 64 kbit/s unrestricted (service 1)/speech (service 2) (Note 2) 00000110 spare 00000111 reserved for 2 x 64 kbit/s unrestricted 00001000 reserved for 384 kbit/s unrestricted Fascicle VI.8 - Rec. Q.763 PAGE49 00001001 reserved for 1536 kbit/s unrestricted 00001010 reserved for 1920 kbit/s unrestricted 00001011 to spare 11111111 Note 1 - The initial mode is speech. Note 2 - The initial mode is 64 kbit/s unrestricted. 3.36 User service information The format of the user service information parameter field is shown in Figure 36/Q.763. This format is the same as the bearer capability information element from Recommendation Q.931 and not all capabilities coded here are supported at this time. Figure 36/Q.763 - T1101560-89 The following codes are used in the subfields of the user service information parameter field: a) Extension indicator (ext) 0 octet continues through the next octet (e.g. octet 2 to 2a, 2a to 2b, 3 to 3a) 1 last octet PAGE26 Fascicle VI.8 - Rec. Q.763 b) Coding standard 00 CCITT standardized coding as described below 01 reserved for other international standards (Note) 10 national standard (Note) 11 standard defined for the network (either public or private) present on the network side of the interface (Note) Note - These other coding standards should only be used when the desired bearer capability cannot be represented with the CCITT standardized coding. c) Information transfer capability 00000 speech 01000 unrestricted digital information 01001 restricted digital information 10000 3.1 kHz audio 10001 7 kHz audio 11000 video All other values are reserved d) Transfer mode 00 circuit mode 10 packet mode All other values are reserved e) Information transfer rate (octets 2 and 2b) (Note 1) 00000 This code shall be used for packet-mode calls 10000 64 kbit/s 10001 2 x 64 kbit/s (Note 2) 10011 384 kbit/s 10101 1536 kbit/s 10111 1920 kbit/s All other values are reserved. Note 1 - When octet 2b is omitted, the bearer capability is bidirectional symmetric at the information transfer rate specified in octet 2. When octet 2b is included, the information rate in octet 2 refers to the origination to destination direction. Note 2 - For this case, the coding of octets 1 and 2a refer to both 64 kbit/s circuits. f) Structure 000 default (Note 1) 001 8 kHz integrity (Note 2) 100 service data unit integrity 111 unstructured Fascicle VI.8 - Rec. Q.763 PAGE49 All other values are reserved. Note 1 - If octet 2a is omitted, or the structure field is coded 000, then the value of the structure attribute is according to the following: Transfer Transfer Structure mode capability circuit speech 8 kHz integrity circuit unrestricted 8 kHz integrity digital circuit restricted 8 kHz integrity digital circuit audio 8 kHz integrity circuit video 8 kHz integrity packet unrestricted service data unit integrity digital Note 2 - When the information transfer rate 2 x 64 kbit/s is used, 8 kHz integrity with Restricted Differential Time Delay (RDTD) is offered. g) Configuration 00 point-to-point All other values are reserved. If omitted, the configuration is assumed to be point-to-point. h) Establishment 00 demand All other values are reserved. If omitted, the establishment is assumed to be demand. i) Symmetry 00 bidirectional symmetric All other values are reserved. If omitted, the symmetry is assumed to PAGE26 Fascicle VI.8 - Rec. Q.763 be bidirectional symmetric. j) Layer identification 00 reserved 01 user information layer 1 protocol 10 user information layer 2 protocol 11 user information layer 3 protocol Note - Bits 5-1 of the same octet represent the corresponding identification as per points k), l) and m) below. If octet 3, 4 or 5 is omitted, the corresponding user information protocol is assumed to be undefined. k) User information layer 1 protocol identification 00001 CCITT standardized rate adaption V.110/X.30. This implies the presence of octet 3a defined in S 3.36 k) 1), and optionally octets 3b, 3c and 3d defined in S 3.36 k) 2) below. 00010 Recommendation G.711 m-law 00010 Recommendation G.711 A-law 00100 Recommendation G.721 32 kbit/s ADPCM and Recommendation I.460 00101 Recommendations G.722 and G.724 for 7 kHz audio 00110 Recommendation G.735 for 384 kbit/s video 00111 non-CCITT standardized rate adaption. This implies the presence of octet 3a, and optionally 3b, 3c and 3d. The use of this codepoint indicates that the user rate specified in octet 3a is defined in accordance with the non-CCITT standardized rate adaption scheme. Additionally, octets 3b, 3c and 3d, if present, are defined consistent with the specified rate adaption. 01000 CCITT standardized rate adaption V.120. This implies the presence of octet 3a defined in S 3.36 k) 1), octet 3b defined in S 3.36 k) 3), and optionally octets 3c and 3d defined in S 3.36 k) 2) below. 01001 CCITT standardized rate adaption X.31 HDLC flag stuffing. All other values are reserved. Note - Octet 3 shall be omitted if the transfer mode is "circuit-mode", the information transfer capability is "unrestricted digital information" or "restricted digital information" and the user information layer 1 protocol is not to be identified to the network; octet 3 may be omitted if the transfer mode is "packet-mode"; otherwise octet 3 shall be present. 1) Octet 3a for layer 1 rate adaption (see Figure 37/Q.763) Figure 37/Q.763 - T1121570-89 - The synchronous/asynchronous indicator is coded: 0 synchronous 1 asynchronous Octets 3b to 3d may be omitted in case of synchronous user rates. - The negotiation indicator is coded: 0 in-band negotiation not possible 1 in-band negotiation possible Note - See Recommendations V.110 and X.30 Fascicle VI.8 - Rec. Q.763 PAGE49 - The user rate is coded: 00000 rate indicated by Rec. I.460 E-bits 00001 0.6 kbit/s Rec. V.6 and X.1 00010 1.2 kbit/s Rec. V.6 00011 2.4 kbit/s Rec. V.6 and X.1 00100 3.6 kbit/s Rec. V.6 00101 4.8 kbit/s Rec. V.6 and X.1 00110 7.2 kbit/s Rec. V.6 00111 8.0 kbit/s Rec. I.460 01000 9.6 kbit/s Rec. V.6 and X.1 01001 14.4 kbit/s Rec. V.6 01010 16.0 kbit/s PAGE26 Fascicle VI.8 - Rec. Q.763 Rec. I.460 01011 19.2 kbit/s Rec. V.6 01100 32.0 kbit/s Rec. I.460 01110 48.0 kbit/s Rec. V.6 and X.1 01111 56.0 kbit/s Rec. V.6 10101 0.1345 kbit/s Rec. X.1 10110 0.100 kbit/s Rec. X.1 10111 0.075/1.2 kbit/s Rec. V.6 and X.1 (Note) 11000 1.2/0.075 kbit/s Rec. V.6 and X.1 (Note) 11001 0.050 kbit/s Rec. V.6 and X.1 11010 0.075 kbit/s Rec. V.6 and X.1 11011 0.110 kbit/s Fascicle VI.8 - Rec. Q.763 PAGE49 Rec. V.6 and X.1 11100 0.150 kbit/s Rec. V.6 and X.1 11101 0.200 kbit/s Rec. V.6 and X.1 11110 0.300 kbit/s Rec. V.6 and X.1 11111 12 kbit/s Rec. V.6 and X.1 All other values are reserved. Note - The first rate is the transmit rate in the forward direction of the call. The second rate is the transmit rate in the backward direction of the call. 2) Octets 3b, 3c and 3d for Recommendations V.110/X.30 rate adaption (see Figure 38/Q.763) Figure 38/Q.763 - T112580-89 - Intermediate rate indicator is coded: 00 not used 01 8 kbit/s 10 16 kbit/s 11 32 kbit/s - Network independent clock (NIC) on transmission (TX) indicator is coded: 0 not required to send data with NIC 1 required to send data with NIC Note - Refers to transmission in the forward direction of the call, see Recommendations V.110 and X.30 - Network independent clock (NIC) on reception (Rx) indicator is coded: 0 cannot accept data with NIC (i.e. sender does not support this optional procedure) 1 can accept data with NIC (i.e. sender does support this optional procedure) Note - Refers to transmission in the backward direction of the call, see Recommendations V.110 and X.30. - Flow control on transmission (Tx) indicator is coded: 0 not required to send data with flow control mechanism 1 required to send data with flow control mechanism PAGE26 Fascicle VI.8 - Rec. Q.763 Note - Refers to transmission in the forward direction of the call, see Recommendations V.110 and X.30. - Flow control on reception (Rx) indicator is coded: 0 cannot accept data with flow control mechanism (i.e. sender does not support this optional procedure) 1 can accept data with flow control mechanism (i.e. sender does support this optional procedure) Note - See Recommendations V.110 and X.30. - Number of stop bits indicator is coded: 00 not used 01 1 bit 10 1.5 bits 11 2 bits - Number of data bits indicator, including parity bit if present, is coded: 00 not used 01 5 bits 10 7 bits 11 8 bits - Parity indicator is coded: 000 odd 010 even 011 none 100 forced to 0 101 forced to 1 All other values are reserved - Duplex mode indicator is coded: 0 half duplex 1 full duplex - modem type indicator is coded according to network specific rules. 3) Octet 3b for Recommendation V.120 rate adaption (see Figure 39/Q.763) Figure 39/Q.763 - T1110150-88 - Rate adaption header/no header indicator is coded: 0 rate adaption header not included 1 rate adaption header included - Multiple frame establishment support in data link indicator is coded: 0 multiple frame establishment not supported, only UI frames Fascicle VI.8 - Rec. Q.763 PAGE49 allowed 1 multiple frame establishment supported - Mode of operation indicator is coded: 0 bit transparent mode of operation 1 protocol sensitive mode of operation - Logical link identifier (LLI) negotiation indicator is coded: 0 default, LLI = 256 only 1 full protocol negotiation (Note) Note - A connection over which protocol negotiation will be executed is indicated in bit 2 of octet 3b. - Assignor/assignee indicator is coded: 0 message originator is "default assignee" 1 message originator is "assignor only" - In-band/out-of-band negotiation indicator is coded: 0 negotiation is done with USER INFORMATION messages on a temporary signalling connection 1 negotiation is done in-band using logical link zero l) User information layer 2 protocol identification 00010 Recommendation Q.921 (I.441) 00110 Recommendation X.25, link level All other values are reserved. If the transfer mode is "packet mode", this octet shall be present. In other cases, the octet is present only if the protocol is to be identified to the network. m) User information layer 3 protocol identification 00010 Recommendation Q.931 (I.451) 00110 Recommendation X.25, link level All other values are reserved. The octet is present only if the protocol is to be identified to the network. 3.37 User-to-user indicators The format of the user-to-user indicators parameter field is shown in Figure 40/Q.763. Figure 40/Q.763 - CCITT 73370 The following codes are used in the user-to-user indicators parameter field: bit A Type 0 request 1 response PAGE26 Fascicle VI.8 - Rec. Q.763 If bit A equals 0 (request): bits C B: Service 1 0 0 no information 0 1 spare 1 0 request, not essential 1 1 request, essential bits E D: Service 2 0 0 no information 0 1 spare 1 0 request, not essential 1 1 request, essential bits G F: Service 3 0 0 no information 0 1 spare 1 0 request, not essential 1 1 request, essential bit H Spare If bit A equals 1 (response): bits C B: Service 1 0 0 no information 0 1 not provided 1 0 provided 1 1 spare bits E D: Service 2 0 0 no information 0 1 not provided 1 0 provided 1 1 spare bits G F: Service 3 0 0 no information 0 1 not provided 1 0 provided 1 1 spare Fascicle VI.8 - Rec. Q.763 PAGE49 bit H Spare 3.38 User-to-user information The format of the user-to-user information parameter is shown in Figure 41/Q.763. Figure 41/Q.763 - T1110150-88 The format of the user-to-user information parameter field is coded identically to the protocol discriminator plus user information field described in Recommendation Q.931, S 4.5.29. 4 ISDN user part messages and codes In the following tables the format and coding of ISDN user part messages is specified. For each message, a list of the relevant parameters is given and for each parameter: - a reference to the section where the formatting and coding of the parameter content is specified; - the type of the parameter. The following types are used in the tables: F = mandatory fixed length parameter; V = mandatory variable length parameter; O = optional parameter of fixed or variable length; - the length of the parameter. The value in the table includes: - for type F parameters the length, in octets, of the parameter content; - for type V parameters the length, in octets, of the length indicator and of the parameter content. The minimum and the maximum length are indicated; - for type O parameters the length, in octets, of the parameter name, length indicator and parameter content. For variable length parameters the minimum and maximum length is indicated. For each message type, type F parameters and the pointers for the type V parameters must be sent in the order specified in the tables. The routing label and circuit identification code fields, which are transmitted ahead of the message type field if required are not shown. Parameter names, pointers to mandatory variable fields and the optional part, and length indicators appear in the message in accordance with Figure 3/Q.763 and are not shown explicitly in Tables 5/Q.763 to 28/Q.763. TABLE 5/Q.763 Message type: Address complete Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Backward call indicators 3.4 F 2 Optional backward call indicators 3.24 O PAGE26 Fascicle VI.8 - Rec. Q.763 3 Cause indicators 3.10 O 4-? Connected number 3.14 O 4-12 Call reference 3.6 O 7 User-to-user indicators 3.37 O 3 User-to-user information 3.38 O 3-131 a) Access transport 3.2 O 3-? End of optional parameters 3.17 O 1 a) Some networks may only support up to 35 octets. Fascicle VI.8 - Rec. Q.763 PAGE49 TABLE 6/Q.763 Message type: Answer Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Backward call indicators 3.4 O 4 Optional backward call indicators 3.24 O 3 Call reference 3.6 O 7 User-to-user indicators 3.37 O 3 User-to-user information 3.38 O 3-131 a) Connected number 3.14 O PAGE26 Fascicle VI.8 - Rec. Q.763 4-12 Access transport 3.2 O 3-? End of optional parameters 3.17 O 1 a) Some networks may only support up to 35 octets. TABLE 7/Q.763 Message type: Call progress Parameter Reference (S) Type Length (octets) Message type 2.1 F 1 Event information 3.18 F 1 Cause indicators 3.10 O 4-? Call reference 3.6 O 7 Fascicle VI.8 - Rec. Q.763 PAGE49 Backward call 3.4 O 4 indicators Optional backward 3.24 O 3 call indicators Access transport 3.2 O 3-? User-to-user 3.37 O 3 indicators User-to-user 3.38 O 3-131 a) information Redirection number 3.30 O 5-12 End of optional 3.17 O 1 parameters a) Some networks may only support up to 35 octets. PAGE26 Fascicle VI.8 - Rec. Q.763 TABLE 8/Q.763 Message type: Circuit group query response Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Range and status a) 3.27 V 2 Circuit state indicator 3.12 V 3-33 a) The status subfield is not present. TABLE 9/Q.763 Message type: Circuit group reset acknowledgement Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Range and status 3.27 Fascicle VI.8 - Rec. Q.763 PAGE49 V 3-34 TABLE 10/Q.763 Message type: Confusion Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Cause indicators 3.10 V 3-? End of optional parameters 3.17 O 1 PAGE26 Fascicle VI.8 - Rec. Q.763 TABLE 11/Q.763 Message type: Connect Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Backward call indicators 3.4 F 2 Optional backward call indicators 3.24 O 3 Connected number 3.14 O 4-12 Call reference 3.6 O 7 User-to-user indicators 3.37 O 3 User-to-user information 3.38 Fascicle VI.8 - Rec. Q.763 PAGE49 O 3-131 a) Access transport 3.2 O 3-? End of optional parameters 3.17 O 1 a) Some networks may only support up to 35 octets. TABLE 12/Q.763 Message type: Continuity Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Continuity indicators 3.16 F 1 TABLE 13/Q.763 Message type: Facility reject Parameter Reference Type Length (S) PAGE26 Fascicle VI.8 - Rec. Q.763 (octets) Message type 2.1 F 1 Facility indicator 3.19 F 1 Cause indicators 3.10 V 3-? User-to-user indicators 3.37 O 3 Call reference 3.6 O 7 End of optional parameters 3.17 O 1 TABLE 14/Q.763 Message type: Information Parameter Reference Type Length (S) (octets) Message type Fascicle VI.8 - Rec. Q.763 PAGE49 2.1 F 1 Information indicators 3.21 F 2 Calling party's category 3.9 O 3 Calling party number 3.8 O 5-12 Call reference 3.6 O 7 Connection request 3.15 O 7-9 Access transport 3.2 O 4-? End of optional parameters 3.17 O 1 TABLE 15/Q.763 PAGE26 Fascicle VI.8 - Rec. Q.763 Message type: Information request Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Information request indicators 3.22 F 2 Call reference 3.6 O 7 End of optional parameters 3.17 O 1 Fascicle VI.8 - Rec. Q.763 PAGE49 TABLE 16/Q.763 Message type: Initial address Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Nature of connection indicators 3.23 F 1 Forward call indicators 3.20 F 2 Calling party's category 3.9 F 1 Transmission medium requirement 3.35 F 1 Called party number 3.7 V 4-11 Transit network selection a) 3.34 PAGE26 Fascicle VI.8 - Rec. Q.763 O 4-? Call reference 3.6 O 7 Calling party number 3.8 O 4-12 Optional forward call indicators 3.25 O 3 Redirecting number 3.28 O 4-12 Redirection information 3.29 O 3-4 Closed user group interlock code 3.13 O 6 Connection request 3.15 O 7-9 Original called number 3.26 O Fascicle VI.8 - Rec. Q.763 PAGE49 4-12 User-to-user information b) 3.38 O 3-131 Access transport 3.2 O 3-? User service information c) 3.36 O 4-13 User-to-user indicators 3.37 O 3 End of optional parameters 3.17 O 1 a) For national use only. b) Some networks may only support up to 35 octets. c) This parameter can be repeated in case of an alternate bearer service, in which case the initial parameter represents the initial establishment mode. PAGE26 Fascicle VI.8 - Rec. Q.763 TABLE 17/Q.763 Message type: Release Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Cause indicators 3.10 V 3-? Redirection information 3.29 O 3-4 Redirection number 3.30 O 5-12 Signalling point code a) 3.31 O 4 Access transport 3.2 O 3-? User-to-user information b) 3.38 Fascicle VI.8 - Rec. Q.763 PAGE49 O 3-131 Automatic congestion level 3.3 O 3 End of optional parameters 3.17 O 1 a) For national use only. b) Some networks may only support up to 35 octets. TABLE 18/Q.763 Message type: Release complete Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Cause indicators 3.10 O 5-? End of optional parameters 3.17 O 1 TABLE 19/Q.763 Message type: Subsequent address PAGE26 Fascicle VI.8 - Rec. Q.763 Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Subsequent number 3.32 V 3-10 End of optional parameters 3.17 O 1 Fascicle VI.8 - Rec. Q.763 PAGE49 TABLE 20/Q.763 Message type: User-to-user information Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 User-to-user information 3.38 V 2-130 Access transport 3.2 O 3-? Call reference 3.6 O 7 End of optional parameters 3.17 O 1 TABLE 21/Q.763 Message type: Delayed release (national use) Forward transfer Parameter Reference Type (S) PAGE26 Fascicle VI.8 - Rec. Q.763 Length (octets) Message type 2.1 F 1 Call reference 3.6 O 7 End of optional parameters 3.17 O 1 TABLE 22/Q.763 Message type: Suspend Resume Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Suspend/Resume indicators 3.33 F 1 Call reference 3.6 O 7 End of optional parameters Fascicle VI.8 - Rec. Q.763 PAGE49 3.17 O 1 TABLE 23/Q.763 Message type: Blocking Blocking acknowledgement Continuity check request Loop back acknowledgement (national use) Overload (national use) Reset circuit Unblocking Unblocking acknowledgement Unequipped circuit identification code (national use) Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 TABLE 24/Q.763 Message type: Call modification completed Call modification request Call modification reject Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Call modification indicators 3.5 F 1 Call reference 3.6 O 7 PAGE26 Fascicle VI.8 - Rec. Q.763 User-to-user information 3.38 O 3-131 a) End of optional parameters 3.17 O 1 a) Some networks may only support up to 35 octets. TABLE 25/Q.763 Message type: Circuit group blocking Circuit group blocking acknowledgement Circuit group unblocking Circuit group unblocking acknowledgement Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Circuit group supervision message type 3.11 F 1 indicator Range and status 3.27 V 3-34 TABLE 26/Q.763 Message type: Circuit group reset Circuit group query Parameter Reference Fascicle VI.8 - Rec. Q.763 PAGE49 (S) Type Length (octets) Message type 2.1 F 1 Range and status a) 3.27 V 2 a) The status subfield is not present. TABLE 27/Q.763 Message type: Facility accepted Facility request a) Parameter Reference Type Length (S) (octets) Message type 2.1 F 1 Facility indicator 3.19 F 1 User-to-user indicators 3.37 O 3 Call reference 3.6 PAGE26 Fascicle VI.8 - Rec. Q.763 O 7 End of optional parameters 3.17 O 1 a) Whether or not the facility request message should contain a connection request parameter requires further study. TABLE 28/Q.763 Message type: Pass-along Parameter Reference (S) Type Length (octets) Message type 2.1 F 1 (00101000) Message type Mandatory fixed Any message in Tables 5/Q.764 to 27/Q.764 which is relevant only part at the "endpoint" of a connection as defined in S 3 of Mandatory variable Recommendation Q.764 part Optional part Fascicle VI.8 - Rec. Q.763 PAGE49 ANNEX A (to Recommendation Q.763) Interpretation of spare codes This Annex describes interpretations which can be applied when a recognized parameter is received containing codes currently indicated as being spare in Recommendation Q.763. This situation can occur when an implementation in accordance to this Recommendation interworks with a future version of this Recommendation. The default interpretations for some of these cases are listed in Table A-1/Q.763. For the remaining cases, listed in Table A-2/Q.763, there is no default which is considered appropriate. It is recommended that the entire parameter in these cases should be considered uninterpretable except as noted. Actions taken after applying the default interpretation of unrecognized fields or after determining that an entire parameter should be considered uninterpretable are described in S 2.10.5.3 of Recommendation Q.764. Application of default interpretations is of particular interest when an unrecognized parameter value is passed on at an intermediate exchange or is used at a connection endpoint. However, other applications are not precluded. TABLE A-1/Q.763 Fields and their default interpretations Field name with unrecognized code Default interpretation Charge indicator Charge Called party's status indicator No indication Called party's category indicator No indication Calling party category Handle as an ordinary call Address presentation restricted indicator Presentation restricted Cause indicator-location (see note) Cause value (unextended) Unspecified: within class xxx Cause value (extended) Unspecified: interworking class Calling party number response indicator Calling party number included Connected number response indicator Connected number included Redirecting number response indicator Redirecting number included Satellite indicator Two satellites Continuity check indicator Continuity check not required Redirecting reason indicator Unknown/unavailable PAGE26 Fascicle VI.8 - Rec. Q.763 Redirection counter Maximum redirections Original redirection reason indicator Unknown/unavailable Redirecting indicator Call forwarded, all redirection information presentation restricted Closed user group indicator Non-CUG call User-to-user (service 1) No information User-to-user (service 2) No information User-to-user (service 3) No information Note - If a network receives an unrecognized location field from other networks, the default interpretation of this field will be the location of the network which sends the unrecognized location, otherwise the default interpretation is "beyond an interworking point". Fascicle VI.8 - Rec. Q.763 PAGE49 TABLE A-2/Q.763 Fields with no default interpretations Uninterpretable field Nature of address Numbering plan Address signal Cause indicator-coding standard a) Cause indicator-recommendation a) Diagnostic User service information (any field) Transmission medium requirement Call modification indicator Event indicator Facility indicator Circuit state indicator Automatic congestion level Circuit group supervision message type a) Cause value interpreted as if coded "unspecified: interworking class" (1111111) and the location field interpreted as if coded "Beyond Interworking Point" (1010). PAGE26 Fascicle VI.8 - Rec. Q.763