UNI Signalling 4.0. Scope Connection Types Call Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary.

Transcription

1 Signalling 4.0 Topics Scope ion Types Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary Page 1

2 Scope of Signalling User-User Signalling User-Network Signalling Network-Network Signalling Control Signalling control protocol is used to establish, maintain, and clear virtual channel connections between a user and network User Network or NNI Control Signalling Control Signalling Virtual Channel ions Interface or NNI Page 2

3 Signalling 4.0 Delta from Q.2931 etc. Extensions for parameterized QoS, ABR, LIJ Some restrictions Signalling Protocol Stack Q.931 Q.2931 Q.921 LAPD I.430/ SSCOP ATM SONET/DS3 ISDN ATM Page 3

4 Topics Scope ion Types Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary Permanent vs. Switched ions PVC-Permanent Virtual Circuits Statically configured via Network Management SVC-Switched Virtual Circuits Dynamically established via Signalling A Page 4

5 Permanent Virtual ions VPI/VCI VPI/VCI VPI/VCI VPI/VCI Network Management System Long setup time (especially with human intervention) means that connections are left active for long periods of time e.g., days, weeks VPI/VCI tables setup in terminals and switches Switched Virtual ions Signalling Channel (VPI/VCI = 0/5) Signalling Channel (VPI/VCI = 0/5) Processing ATM Switch Switch and terminal exchange signalling messages using the predefined signalling channel, VPI/VCI = 0/5 Page 5

6 Why SVCs? Universal connectivity More efficient resource utilization A Point-to-Point ion Data may flow in one or both directions (unidirectional or bidirectional) Bandwidth may be: Same in both directions (symmetric), or Different in each direction (asymmetric) Page 6

7 Point-to-Multipoint ion Root Data are replicated by the network Data flow only from Root to Leaves Leaves Topics Scope ion Types Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary Page 7

8 Address to Endstation ATM End System Address Format Native E.164 or AESA Public ATM Network Private ATM Switch Private Public ATM End System Address AESA Format Based on ISO NSAP Format Network- Supplied End System- Supplied 39 DCC HO-DSP End System ID SEL SEL 47 IDC HO-DSP End System ID SEL SEL 45 E.164 Number HO HO-DSP End System ID SEL Private Selector (Not used by Network for Routing) Page 8

9 Address Registration Allows automatic configuration Required at the private Optional at the public Network supplies the network prefix User supplies the user part Subaddress Use Subaddress: Used to convey an AESA across a public network which supports only E.164 addresses Also can be used for NSAP Private Address: AESA Subaddress: NSAP or Not Used Private Network Public Address: E.164 Public Network Address Subaddress: : AESA Subaddress IE: Only present if used for NSAP at Private Public Network Private Network A Page 9

10 Selection Within Endstation High Layer Information Type of Application Low Layer Information Type of layer 2 & 3 protocols Selector (AESA Format Only) Optional use within Endstation Supplied by Network End System Id SEL Topics Scope ion Types Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary Page 10

11 Messages and Information Elements Type Length Type Length Value Type Length Value Type Length Message Header IE1 IE2 IE3. Very flexible and extensible encoding 19 message types Around 35 IEs Sample Message Flows Initiate a Accept a Reject a Clear a Page 11

12 Initiate a Proceeding Initiate a - 2 NNI Proceeding Proceeding Page 12

13 Accept a - 1 NNI Proceeding Proceeding Ack Accept a - 2 NNI Proceeding Proceeding Ack Ack Page 13

14 Reject a Proceeding NNI Proceeding Complete Complete A User Clears a Complete Complete NNI or Complete Complete Page 14

15 Network Clears a NNI Complete ion Terminated Complete Root s the First Party Proceeding Ack NNI Proceeding Ack Page 15

16 Root Invites Additional Party Add Party NNI Add Party Ack Proceeding Ack The Party Declines Add Party Add Party Reject NNI Proceeding Complete A Page 16

17 Root Drops a Party Drop Party Drop Party Acknowledge NNI Complete Root Drops the Last Party Complete NNI Complete Page 17

18 Party Drops Itself NNI Drop Party Drop Party Acknowledged Complete Leaf Initiated Join to PMP Network LIJ - network adds Root LIJ - root adds Network LIJ is scalable Allows leaves to take the initiative Page 18

19 Network LIJ - Initial Leaf 1 * Leaf 2 Ack Ack *PNNI support for LIJ is not yet available A Network LIJ - Leaf Join Leaf 1 Leaf 2 Leaf Req Ack A Page 19

20 Topics Scope ion Types Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary Bandwidth - 1 Bandwidth 12 Leaky Bucket Parameters Forward/Backward tagging Requested/Not Requested Best Effort Indication (for use with Peak Rate CLP=0+1 only, and QoS Class 0) List of Allowable Combinations Page 20

21 Bandwidth - 2 Bandwidth: 12 Leaky Bucket Parameters: CLP = 0 CLP =0+1 Forward Peak Cell Rate Sustainable Cell Rate Maximum Burst Size Peak Cell Rate Sustainable Cell Rate Maximum Burst Size Backward Peak Cell Rate Sustainable Cell Rate Maximum Burst Size Peak Cell Rate Sustainable Cell Rate Maximum Burst Size Bandwidth Negotiation NNI (20 Mb/s) (15 Mb/s) (10 Mb/s) (10 Mb/s) (10 Mb/s) (10 Mb/s) Page 21

22 Quality of Service Parameters End to end transit delay Acceptable CDV (Forwards, Backwards) Cumulative CDV (Forwards, Backwards) Cell Loss Ratio (Forwards, Backwards) Encoded as two IEs QoS Classes may also be indicated for backwards compatibility Low Layer Information Layer 3 Protocol Choice: CCITT X.25 packet layer,t.70 ISO 8208, 8473, 8878, 9577 User-Specified Layer 3 Protocol Parameters NLPID, SNAP protocol identification OUI (Organization Unique Identifier) for organization defined protocols A Page 22

23 High Layer Information High Layer Information Type: ISO User Specific High layer profile Vendor-Specific Application identifier OUI (Organization Unique Identifier) for organization-defined applications Topics Scope ion Types Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary Page 23

24 AAL Parameters ATM Adaptation Layer Parameters AAL Type: 1, 3/4, 5, AAL for Voice or User-Defined Subtype (for AAL 1): Null/empty Voice-band based on 64 kbit/s Synchronous Circuit Emulation Asynchronous Circuit Emulation High-quality audio Video A AAL Parameters Cont. ATM Adaptation Layer Parameters for AAL 1 CBR rate: ISDN Rates from 64 to kbit/s, or n x 64 kbit/s Clock recovery type Error correction type Structured Data Transfer Partially Filled Cells ATM Adaptation Layer Parameters for AAL 3/4 MID Size A Page 24

25 AAL Parameters Cont. AAL Parameters for AAL 3/4 or 5: Forward Maximum CPCS-SDU Size Backward Maximum CPCS-SDU Size SSCS Type: Null, Assured SSCOP, Non-assured SSCOP, or Frame relay SSCS AAL Parameters for User-Defined AAL User-defined Contents Bearer Capability Bearer Capability: Bearer Class: BCOB-A, BCOB-C, BCOB-X ATM Transfer Capability (ATC): - CBR (Note B) - CBR with CLR commitment on CLP=0+1 (Note H) - Real time VBR (Note G) - Real time VBR with CLR commitment on CLP=0+1 (Note I) - Non-real time VBR (Note C, Note D) - Non-real time VBR with CLR commitment on CLP=0+1 (Note J) - ABR Susceptibility to clipping: Yes or No User plane connection configuration: - Point-to-Point or Point-to-Multipoint A Page 25

26 Signalling for ABR Two special IEs for ABR parameters Special negotiation and defaulting rules ABR is a special case! Topics Scope ion Types Endpoints Signalling Mechanisms Traffic Contract Service Parameters Futures Summary Page 26

27 Future Work Addressing enhancements Multipoint to point connections Security support Closed user groups ion modify Approved 4.0 Addenda Addressing Security A Page 27