Error 500 - Core dump - InetDaemon's Brain has performed a raw core dump of ATM
PHYSICAL CHARACTERISTICS
- Hardware independent/Media transparent
- Point-to-Point (not a broadcast protocol)
- Asynchronous
- Cell based (all cells same size, therefore easy to predict intervals between data)
- Supports QoS
- Interfaces specified for:
- Encapsulates ISDN (CCITT Q.2391)
- Encapsulates FRAME RELAY
- SDH/SONET (AAL5) - Use as Physical layer (most commonly used)
- IP (AAL5) -
- DSx (AAL5) - Use as physical layer
- SMDS
OSI MODEL RELATIONSHIPS
AAL 0
AAL 3/4 - Message Mode OR Streaming mode
| OSI MODEL | ATM Layers | ||
| NETWORK | CBR | VBR | ABR | UBR | Signalling | ||
| Service Specific Convergence Sublayer | Convergance Sublayer | ATM Adaptation Layer | |
| Common Part Convergence Sublayer | |||
| DATA LINK | Segmentation and Reassembly | ||
| Asynchronous Transfer Mode | |||
| PHYSICAL | Transmission Convergeance | ||
| Physical Medium Dependant | |||
- Service Access Point (SAP)
- ATM Adaptation Layer
- Convergance Sublayer (CS)
- Service Specific Convergence Sublayer (SSCS)
- Common Part Convergance Sublayer (CPCS)
- Segmentation And Reassembly (SAR)
- Convergance Sublayer (CS)
- Service Access Point (SAP)
ATM FRAME FORMAT (53 Bytes)
- 5 byte header (bits - purpose)
- 4 - Generic Flow Control (binary 0000 as default - not defined in standards yet)
- 8 - Virtual Path Identifier
- 12- Virtual Channel Identifier
- 3 - Payload Type Identifier
PTI CELL USAGE ATM User-User
SignallingCongestion
Experienced000 User Data no 0 001 User Data no 1 010 User Data yes 0 011 User Data Yes 1 100 OAM F5 link - - 101 OAM F5 end-to-end - - 110 Resource Management - - 111 Reserved - - - 1 - Cell Loss Priority [yes/no]
- 8 - Header Error Check
- 48 bytes - Payload
ATM NETWORK INTERFACES
- User to Network (UNI)
- Q.2931 - ISDN
- FUNI - Frame Relay
- Network to Network Interface (NNI)
ATM ADDRESSES
NSAP
- IDP - Initial Domain Part
- AFI - Authority Format Identifier
- IDI - Initial Domain Identifier
- DSP - Domain Specific Part
CLASS OF SERVICE
- A - Constant bit rate - no delay
- B - Constant bit rate - delay tolerant
- C - Connection oriented variable bitrate - burst-rate
- D - Connection-oriented & connectionless variable bitrate - burst-rate
- X - ATM-raw
ATM ADAPTATION LAYER TYPES (AAL) and CLASS OF SERVICE (COS) TABLE
| AAL | CLASS | TYPE | NOTES |
|---|---|---|---|
| 0 | A | CBR - Constant Bit Rate | Connection oriented; Constant bit rate. Best suited for voice and video. |
| 2 | B | VBR - Variable Bit Rate | Connection oriented; variable bit rate. Best for delay insensitive applications such as packetized voice, video. |
| 3/4 | C | ABR - Adjustable Bit Rate | Connection oriented; adjustable bit rate traffic. Usable for network applications, but has high complexity/overhead. |
| 5 | D | UBR - Unspecified Bit Rate | Connectionless |
| X |
CIRCUITS
- Permanent Virtual Circuits
- Switched Virtual Circuits
ATM-LANE
ELANs - Emulated LANs each with:
- LAN Emulation Server (LES)
- LAN Configuration Server (LECS)
- Broadcast and Unknown Server (BUS)