B ear er Inde Ind ep en d en t Cal Cal l Cont Con t r o l - B ICC Switch wi tching ing Core Ne Network two rk Signa ign alling lli ng M14/U4
For publ public ic u
IPR IP R applies applies
B IC ICC C in i n 3G 3GPP PP R4
Control plane
BICC CS-2 IP MSC Server
Nc
8
8 4
c 4 P 2 M . I
c 2 I . P M H
MGW
IPR IP R applies applies
H
Nb
User plane
For publ public ic u
MSC Server/ Server / GCS
AAL2/AAL5 RTP ATM or IP
MGW
Bearer Bea rer Inde Ind epend pende ent Call Con ontr trol ol - BIC BICC C - call control protocol - based on ISUP - Separate set of procedures for call control signalling and transport of bearer control signalling - independent of - bearer technology (e.g. IP, ATM) - signalling message transport (e.g. MTP, MTP3b, SIGTRAN)
BICC
For publ public ic u
IPR IP R applies applies
MTP3
MTP3b
M3UA
MTP2
SA A L
SCTP
MTP1
A TM
IP
B IC ICC o v er TDM
B IC ICC o v er A TM
B IC ICC o v er IP
BICC in 3GPP R4 • For IP backbones: bearer-information is transferred between MSSs in BICC through APM-mechanism
.. .. IP IP address: address: 192.168.3.2 192.168.3.2 Port: Port: 5964 5964 Codec: Codec: AMR AMR mode mode 7 7 .. ..
Bearer information carried inside call control messages MSC Server
MSC Server IAM
BICC
MGW
For public u
IPR applies
IP: 192.168.3.2 por t: 5964
Sigtran MGW
M3UA SCTP IP
BICC Functional Blocks CMN
SN Control plane
CSF l o r ) t n C o B C C ( r g e r l n a i l e a B n l g l i a S C
Call Control Signalling
CSF
BCF
Call Control Signalling
CSF l o r ) t n C o B C C ( r g e r i n l a l e a B n l g l i a S C
BIWF
BIWF User plane
SN
Bearer Control Signalling
Bearer
BCF
Bearer
SN :
Serving Node – Call Service Function (CSF) with associated Bearer Control Function (BCF)
CMN :
Call Mediation Node – CSF without associated BCF
BIWF :
Bearer Inter-working Function, provides BCF and media mapping/switching function
For public u
IPR applies
Bearer Establishment Modes MSS
MSS BICC:IAM
Forward Bearer establishment direction
ATM and IP bearers
MSS
MSS BICC:IAM
Backward ATM bearers IP bearers only if originating side is another vendor
Bearer establishment direction
MGW For public u
IPR applies
MGW
Two ways to establish a bearer 1) ATM: separate bearer control signalling: AAL-Type-2 Signalling 2) IP:
bearer information tunneled in call control and call bearer control messages: IPBCP
MSS
Call Control Signalling BICC or SIP
MSS IP backbone:
the IPBCP protocol is tunneled inside H.248 and BICC (or SIP) via the MSC Servers. H.248
H.248 ATM backbone:
separate bearer control signalling: AAL-Type-2 signalling Bearer Control Signalling e.g: AAL2 signalling
MGW For public u
IPR applies
MGW
Main BICC call control related messages -1Q1902.3
For public u
Message
Code
Description
ACM
0000 0110
Address Complete Message
ANM
0000 1001
Answer Message
APM
0100 0001
Application Transport Message
CPG
0010 1100
Call Progress
CON
0000 0111
Connect
IAM
0000 0001
Initial Address Message
IDR
0011 0110
Identification Request
IRS
0011 0111
Identification Response
INF
0000 0100
Information
INR
0000 0011
Information Request
IPR applies
Main BICC call control related messages -2Q1902.3
For public u
IPR applies
Message
Code
Description
REL
0000 1100
Release
RES
0000 1110
Resume
RLC
0001 0000
Release Complete
SAM
0000 0010
Subsequent Address Message
SGM
0011 1000
Segmentation
SUS
0000 1101
Suspend
USR
0010 1101
User-to-User Information
Main BICC Maintenance related messages -1Q1902.3 Message
Code
Description
CGB
0001 1000
Circuit / CIC Group Blocking
CGBA
0001 1010
Circuit / CIC Group Blocking Acknowledgement
GRS
0001 0111
Circuit / CIC Group Reset
GRA
0010 1001
Circuit / CIC Group Reset Acknowledgement
CGU
0001 1001
Circuit / CIC Group Unblocking
CGUA
0001 1011
CFN
0010 1111
Circuit / CIC Group Unblocking Acknowledgement Confusion
RSC
0001 0010
Reset Circuit / CIC message
For public u
IPR applies
General BICC PDU format (ASN1)
For public u
IPR applies
Format of BICC messages • Formats and codes for BICC protocols are specified in ITU-T Q.1902.3 • They are very similar to ISUP messages.
CIC Message type code Mandatory fixed part Mandatory variable part Optional part
For public u
IPR applies
CIC (Call Instance Code) • CIC in the BICC protocol is used to identify a signalling relation between peer BICC entities and to associate all the PDUs to that relation. • CIC allocates a signalling message to the (virtual) channel, carrying the call. • Bilateral agreement is required with regard to the CIC values provisioned.
8
7
6
5
4 CIC
MSB
For public u
IPR applies
3
2
1 LSB
1
CIC
2
CIC
3
CIC
4
Application Transport Mechanism – APM -1• APM (ITU-T Q.765.5) is used to transmit bearer related information in BICC messages • The application, using APM for bearer control, is called Bearer Association Transport – Application Service Element (BAT- ASE) • The application is running in parallel to call control instance in the node • Application specific data may be sent in CC messages or as a separate APM message.
appl
appl
CC
CC CC message + application data (e.g. BICC:IAM) application data
(e.g. BICC:APM)
CC message + application data (e.g. BICC:CPG)
For public u
IPR applies
Application Transport Mechanism – APM -2• APM for BICC carries among others – Action indicator (forward/backward) – BNC ID (reference used to associate the bearer with a call) – BIWF address (MGW address) – Codec(s) – Tunneling related information (used/not used, bearer control payload) • Carried in APP parameter of various BICC call control messages: ACM, ANM, APM, CPG, CON, IAM, PRI
MSS BAT-ASE
MSS param
APP
param
IAM
e.g. IAM or APM message For public u
IPR applies
BAT-ASE
Application Transport Parameter (APP)
000010= BAT ASE application used
ext=0 octet 1a present
8
7
ext. ext. Sequence Indicator 1=New sequence 0=Subsequent
6
4
3
2
Application Context Identifier (BAT-ASE)
1 LSB
MSB spare SI
SNI
RCI
APM Segmentation Indicator
ext.
Segmentation local reference
7
6
5
4
2 3a
n 1=send notification 3
2
1
000000=Final segment 000001 to 001001= segment number
1
Length indicator 1
2
Compatibility information 1
3
Identif ier 2
4 m
Length indicator 2 Compatibility Information 2 Content 2 : For public u
IPR applies
Send Notification
4 Indicator
Identif ier 1
Content 1
Release Call Indicator 1=Release call
3
APM u ser in for mat ion
8
1 1a
ext. ext.
5
n
Contents of APM identifiers -1Value
IE name
Information
0000 0001
Action Indicator
Can have codes like “connect forward”, “connect backward” etc.
0000 0010
Backbone Network Connection Identifier (BNC_ID) Bearer Interworking Function address (BIWF)
Identifies the logical connection between a local and remote termination. (Similar to the port in the IP technology)
0000 0100
Codec list
In the codec list, single codec information elements are listed in decreasing order of preference level.
0000 0101
Single codec
Has a field called Organization identifier and codec information subfield. Subfield has information about the codec type and codec configuration.
0000 0111
Bearer Network Connection Characteristics
Identifies the bearer used e.g. IP/RTP, AAL1, AAL2, TDM etc.
0000 0011
For public u
IPR applies
ATM AAL2 level address which is needed for the ATM AAL2 connection setup. (Similar to the IP address in the IP technology) NSAP format
Contents of APM identifiers -2Value
IE name
Information
0000 0110
BAT compatibility report
Instructions on received, unrecognized information
0000 1000
Bearer Control information
Contains PDU (Protocol Data Unit) of BCTP
0000 1001
Bearer control tunnelling
Indicates whether tunnelling is used or not
0000 1010
Bearer Control Unit identifier
Contains information about the BCU. It includes Network ID and Local BCU-ID. A logical MGW identifier which can be used for optimal MGW selection purposes.
0000 1011
Signal
Signal to be applied
0000 1110
Signal type
Indicates the signal type e.g. DTMF tones, dial tone, ringing tone, busy tone etc.
0000 1100
Bearer redirection capability
Indicates whether bearer redirection capability is supported at sending node and also indicates options within the capability.
0000 1000
Duration
Duration of a signal in milliseconds.
For public u
IPR applies
Action Indicator: used for a lot of indications • Bearer Setup Control, for example – – – – –
no indication connect backward connect forward connect forward, no notification connect forward plus notification required
• Bearer Setup Indication, for example – connected
• Codec Selection and Modification, for example – – – – –
selected codec modify codec successful codec modification codec modification failure mid-call codec negotiation
• DTMF Interaction, for example – – – – For public u
start signal, notify start signal, no notify stop signal, notify stop signal, no notify IPR applies
Action Indicator (AI): usage in BICC:IAM and BICC:APM • IAM contains one of the following action indicator values: “connect forward ” or “connect backward ”
• APM (as IAM response) without codec negotiation: “connect forward, no notif ication”
• APM (as IAM response) with codec negotiation: “connect fo rward, no notif ication + selected codec”, “selected codec ”
• APM, if the out of band bearer establishment notification is requested from the peer MSS without codec negotiation (i.e. BICC:APM notifies the peer MSS about an established bearer): “connect forward, plus noti fication ”
• APM, if the out of band bearer establishment notification is requested from the peer MSS with codec negotiation: “connect fo rward, plus not ification + selected codec”
• APM – as out of band bearer establishment notification to the peer MSS: “connected”
• APM – transferring only Bearer Control Information (IPBCP) in case of IP tunneling: no action indicator . For public u
IPR applies
Codec list CODEC LIST
Single Codec IE
Single codec IE
Organizatio n ID
Organization Identifier
Single codec IE
0x00
no indication
0x01
ITU-T
0x02
ETSI
Codec type (codec ID)
Single codec IE
Codec configuration
Codec Type (Codec ID)
ITU-T
Only if codec negotiation is used
For public u
ZJ FI:
IPR applies
ETSI
0x00
No indication
0x00
GSM – FR
0x01
G.711 (64 kbps, A-law)
0x01
GSM – HR
0x02
G.711 (64 kbps, u-law)
0x02
GSM – EFR
0x03
GSM – FR AMR
0x04
GSM – HR AMR
0x05
UMTS – AMR
0x06
UMTS – AMR2
Tunneling bearer information IPBCP (Q.1970)
SDP (RFC2327)
MSS
BCTP
MSS
Nc
(Q.1990)
APM
IPBCP
(Q.765.5)
BICC
(Q.1970)
Mc
Mc
(Q.1902.2)
SDP (RFC2327)
M3UA
BCTP
SCTP
(Q.1990) IP_BB
IP
MEGACO (H.248)
MGW
MGW
SCTP IP
For public u
IPR applies
IPBCP – IP Bearer Control Protocol • Establishes and allows the modification of IP bearers. • Encoded by Session Description Protocol (SDP; text) • Four messages: • Request
- Sent by a BIWF to initiate an IP bearer establishment or modification request.
• Accepted
- Sent by a BIWF that receives an IP bearer establishment or modification message if it accepts the request.
• Confused
- Sent by a BIWF in response to an IP bearer establishment or modification message if it cannot process the received message.
• Rejected
- Sent by a BIWF in response to an IP bearer establishment or modification message if it rejects the request
For public u
IPR applies
IPBCP in SDP format SDP version (v) : 0 Owner/Creator, Session ID (o) :
Owner Username : - (not used by IPBCP) Session ID : 0 (not used by IPBCP) Session Version : 0 Owner Network Type : IN (internet) Owner Address Type : IPv4 or IPv6
v=0 SDP o= - 0 0 IN IP4 10.33.16.136 s= IP Tunneling c= IN IP4 10.33.16.136 t= 0 0 a= ipbcp:1 Request m= audio 1026 RTP/AVP 96 a=rtpmap: 96 VND.3GPP.IUFP/16000
Owner Address : IP address of the MGW Session n ame (s): Session type (ignored when received) Connection Inform ation (c):
Connection Network Type : IN Connection Address Type : IPv4 or IPv6 Connection Address : IP address of the MGW Time Description, active time (t) :
Session Start Time : 0 Session Stop Time : 0 (0 indicate permanent session)
Session Attri bute (a) :
Session Attribute Fieldname : IPBCP protocol version : 1
Media Descript ion , name and address (m):
Media Type : audio or video Media P ort : port number value Media Proto: RTP/AVP Media Format : Media Att rib ute (a) :
Media Attribute Fieldname : rtpmap or fmtp Media Format : Multi-Purpose Internet Mail Extension Type :
IPBCP command type : Request/Accepted/Confused/Rejected For public u
IPR applies
Codecs represented in SDP Codec
SDP representation
Codec
SDP representation
AMR
m=audi o 1234 RTP/ AVP 96 a=r t pmap: 96 AMR/ 8000 a=f mt p: 96 mode- set =1, 2, 3, 4, 5, 6, 7
G.723.1 Ann ex A
EFR
m=audi o 1234 RTP/ AVP 103 a=r t pmap: 103 GSM- EFR/ 8000
m=audi o 1234 RTP/ AVP 4 a=r t pmap: 4 G723/ 8000 a=f mt p: 4 annexa=yes
G.729a
FR
m=audi o 1234 RTP/ AVP 3 a=r t pmap: 3 GSM/ 8000
m=audi o 1234 RTP/ AVP 18 a=r t pmap: 18 G729A/ 8000
G.729a Ann ex B
G.711 A-law
m=audi o 1234 RTP/ AVP 8 a=r t pmap: 8 PCMA/ 8000
m=audi o 1234 RTP/ AVP 18 a=r t pmap: 18 G729A/ 8000 a=f mt p: 18 annexb=yes
m=audi o 1234 RTP/ AVP 0 a=r t pmap: 0 PCMU/ 8000
iLBC
m=audi o 1234 RTP/ AVP 97
G.711 u-law G.723.1
m=audi o 1234 RTP/ AVP 4 a=r t pmap: 4 G723/ 8000
For public u
IPR applies
a=r t pmap: 97 i LBC/ 8000 Clearmode
m=audi o 1234 RTP/ AVP 100 a=r t pmap: 100 CLEARMODE/ 8000
Terms, describing call setup scenarios (1)
Forward call setup:
The bearer connection at Nb is established in the same direction as the initial call setup message at Nc (from A-side MGW towards B-side MGW; SAI=FORW).
Backward call setup:
The bearer connection at Nb is established in the opposite direction as the initial call setup message at Nc (from B-side MGW towards A-side MGW; SAI=BACK).
Delayed MGW selection:
For public u
IPR applies
MGW selection method in the originating MSC Server when the originating MGW is selected after the succeeding MSC Server has selected the MGW (originating MGW selection is based on the MGW of the succeeding MSS). Forward bearer establishment. SAI=DFORW, supported only with ATM bearer currently
Terms, describing call setup scenarios (2) Forward t unnelling:
The initial bearer control protocol message (IPBCP :Request) is tunneled in the same direction as the initial call setup message at Nc (from A-side MGW towards B-side MGW).
Backward tunnelling:
The initial bearer control protocol message (IPBCP :Request) is tunneled in the opposite direction to the initial call setup message at Nc (from B-side MGW towards A-side MGW).
Fast tunnelling:
The initial bearer control protocol message (IPBCP :Request) is exchanged in the first IAM – APM message pair.
Delayed tunnelling:
The initial bearer control protocol message (IPBCP :Request) is exchanged in the second and third APM messages (i.e. after the first IAM – APM message pair).
For public u
IPR applies
Forward IP bearer establishment with fast forward tunneling, no codec negotiation SAI = FORW UPD.STOM = DC
UPD.STOM = DC
5. IAM (APP ( "connect forward", BCU-ID1, BNC Char: IP/RTP BCI = IPBCP1, BCT = Tunneling to be used )) 10. APM (AP P ( "connect forward, no notifification", BCU-ID2, BCI = IPBCP2)) 18. ACM 19. ANM )
. , d n 1 I T ) ( l 1 q e = n e n t p R u O d T n = u d t A n T . e 1 v E
1 P C B P I (
y l p e q R e y i R f y t o f i N . t . 2 o 4 N .
y l p e R d d A
Note: The AddReply and NotifyReq commands are conveyed in the same H.248 message.
3
)
2 P C B P I (
) . t s E y l y C l p p N B e ( e
ACM depends on the terminating side call setup in MSS2.
q R q R e y e f i R d t d o R y o f d M i N . t o 2 o . M . 1 N 7 . 1 1 1
6 1
, ) , d 1 n P 2 I T y l l ( e C p q n B P e n I , e R u 1 R d T t = d d = d t p A A n O . . e 7 6 v n u E T
13. User Plane “ establis hed” . 14. NbUP Init 15. NbUP Init Ack
Fast forward tunneling is initiated only without codec negotiation and only with forward bearer establishment. For public u
IPR applies
) . t s E C N ( e B ( )
2 P C y B l P p I
y l p e q R q R e y e f y i i R f t t R y y o o f f i t N i t o . o N . 9 N 7 N 1 . . 8
6 1
Note: The AddReply and NotifyReq commands are conveyed in the same H.248 message.
The purple parts are the IP tunneling specific it ems.
Forward IP bearer establishment with delayed forward tunneling and codec negotiation SAI = FORW UPD.STOM = CN
3. IAM (APP ( "connect forward", BCU-ID1, BNC Char: IP/RTP, BCT = Tunneling to b e used , supported codec list ))
UPD.STOM = CN
6. APM (AP P ( "connect forw, no notif+sel cdc", BCUID2, selected c odec, available codec li st )) 11. APM (APP (BCI = IPBCP1)) 16. APM (APP (BCI = IPBCP2)) 24. ACM
, c e d o c o ) n 2 , = 1 t p T ( O
, ) C . ) t ) N 1 s 2 B ) P E . P , d C y C h c y l s l y C n y B i e I l y l N p p B l P l l b p d P I B e ( p p t I e ( e o e e ( e a q R R s c n q R q y n R e f y R E e f e d i u d d ( d R t e t R i
25. ANM
ACM depends on the terminating side call setup in MSS2.
q n t T o y o R o y e u d q o = d f e c f i i R T A e t M t N o M N t . n . R l d . . e 8 o 0 M 8 o . 2 d e d . 1 N 3 v N d s E A . 1 7 . 2 o 1 . 9 2 1 M 2 .
,
c e d o c ) , 2 2 t = T ( p q O e n u R T d
d A . 4
7
)
) .
4 1
. 2 2
, t 2 s 1 ) , P E P d C C n y y C l y B l y B I l N p l l p P p I p P e B e I ( e ( e ( n e q n R e R q R R q y y e f u d f d e T i i t t R d R = o R y y o o f t M f A d i t N i . o n t N . e o 5 M v 3 . o . . 3 5 1 N 2 E . 1 N 2 1
19. User Plane “ establis hed” . 20. NbUP Init 21. NbUP Init Ack
Delayed forward tunneling is initiated only with codec negotiation. For public u
IPR applies
The purple parts are the IP tunneling specific it ems.
Forward ATM bearer establishment, no codec negotiation SAI = FORW UPD.STOM = DC
UPD.STOM = DC
3. IAM (APP ( "connect forward", BCU-ID1, BIWF1, BNC Char: ATM AAL2)) 6. APM (AP P ( "connect forward, no notification", BCU-ID2, BNC-ID2, BIWF2)) 15. ACM 16. ANM
) ) l . , t a c ) ) s , n e 1 1 E g F 2 i d o F W F s y l y C c W I W r l N p e , I B I p B 1 B ( B r e e ( y ( a T e q R ( g l q R p y B q i n e e . d e f e t t o R i t s R R s y o R e E M f d d i d u t N d , . d d q . e A o 2 9 o 4 A R D N I 1 . M . . . 2 7 1 3 C 1 N B
ACM depends on the terminating side call setup in MSS2.
) ) 2 . t D s I , - 2 E F , C y C l N 2 W N p I B T ( , B ) B ( e q 2 ( R y 2 e F l D q I y - e f p R W t C R i e d I y o N f d B g R B i t N d A i . o 4 . n d 4 t s A N 1 e . . u 5 3 q 1 e R
8. AAL 2 ERQ 10. AA L2 ECF 11. NbUP Init 12. NbUP Init Ack
For public u
IPR applies
Forward ATM bearer establishment, with codec negotiation SAI = FORW UPD.STOM = CN
3. IAM (APP ( "connect forward", BCU-ID1, BIWF1, BNC Char: ATM AAL2, supported codecs list )) 6. APM (APP ( " connect forw, no notif + selected codec" , BCU-ID2, BNC-ID2, BIWF2, sel codec, avail. codecs li st )) 15. ACM 16. ANM
) . t ) C r s 1 e N o g F E B r n i a n y , , t W e l y C I 2 B l 1 s N p B T . p B ( F t ( e u ) ( e 1 l e y ) W s q q l R E a e F p I R q e R y e f ( , n W e B d i I R R t g q , c i o d c B R e e s f y o d e d R d M i t . o N d d o 9 A d . c . o A 4 N , 1 c 1 . d . 2 o 2 3 D M I 1 . 7
) . t s , C 2 E ACM depends on N y , B F C l the terminating side 2 , W N I T 2 B ) B p e call setup in MSS2. ( 2 ( q F ( q R y D ) l e W I y I p - e f i R B 2 R t C D e d g I N f y o d i n R i B t d t A s d o N . . 4 N 4 e 1 u A . . q 5 3 e 1 R
8. AAL 2 ERQ 10. AA L2 ECF 11. NbUP Init 12. NbUP Init Ack
Differences in red com pared to the previous sl ide.
For public u
IPR applies
UPD.STOM = CN
Backward ATM bearer establishment, no codec negotiation SAI = BACK UPD.STOM = DC
UPD.STOM = DC 3. IAM (APP ( "connect backward", BCU-ID1, BIWF1, BNC-ID1, BNC Char: ATM AAL2)) 12. ACM 13. ANM ) . t , , s c C 1 E e N I d B D y C l o , C c 1 N p , F N B ) ( e 1 B ( 1 q R T I ) ( W y 1 y l F e f q B D i W t e g I p I R e y o n B f R i i t N d t s R d . o 1 d e d N A u 1 q A . . e . 0 1 R 2 1
NbUP (IuUP also) initialisation is executed end-toend and it is always done in forward direction regardless of the bearer establishment direction.
For public u
IPR applies
ACM depends on the terminating side call setup in MSS2.
) C . t N ) s B l E a , n C y 1 i g F s l y N l p r p B W ( e I e e q R B , r y , 1 a R e f e 2 I d R i D t B T d y o ( h f i N q i s A . t e l . 6 o 1 R b N a 1 d t . s 0 d E 1 A . 4
5. ERQ 7. ECF 8. NbUP Init 9. NbUP Init Ack
Backward ATM bearer establishment with codec negotiation SAI = BACK UPD.STOM = CN
UPD.STOM = CN
3. IAM (APP ( "connect backward", BCU-ID1, BNC-ID1, BIWF1, BNC Char: ATM AAL2, supported codec list )) 8. APM (APP ( “selected codec", selected codec, available codec list )) 15. ACM 16. ANM ,
c e C d N o B c , o 1 n F
, 1 D I ( ) q c C e e d N o ) , ) B c ( 1 R 1 W I 1 d y F l d d T e ( B D W I p I o t q g c e n B e e t i R M l . R s 9 e d s e d u d d q A A e . . 1 R 2
) . t s E y l y C l p p N B e ( e
R R q y e f d R t o y i o M f i N . t . 0 o 4 1 N 1 . 3 1
, l 1 ) F a ACM depends on the W n g I i terminating side call B , s r , setup in MSS2. e 2 1 D r T I ( - a e q C B e N h R B l s d i d b a A t s . E 4
5. ERQ 7. ECF 11. NbUP Init 12. NbUP Init Ack
Differences in red com pared to the previous sl ide. For public u
IPR applies
) . t s E C y y N l p l p B ( e
e q R y R e f d R i t d f y o A i N . t . 6 o 4 N . 1 3 1
Codec Selection : Tandem Free Operation (TFO) vs Transcoder Free Operation (TrFO) - TFO
For public u
IPR applies
Codec Selection : Tandem Free Operation (TFO) vs Transcoder Free Operation (TrFO) - TrFO : Codec negotiation using BICC APP parameter
For public u
IPR applies
