B-ISDN and ATM (보충)
발표자 : 박종민
jmpark@cs.chonbuk.ac.kr
2000년 2학기
B-ISDN and ATM (보충)
1
Reference Site
• http://myhome.netsgo.com/hl3qvh/ho/ppt/q2931
• http://home.yeojoo.ac.kr/~dwhyun/atm
2000년 2학기
B-ISDN and ATM (보충)
2
Characteristics of ATM
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Uses small, fixed-sized cell
Connection oriented
Bandwidth allocation on demand
Supports multiple service types
Applicable to LAN and WAN
2000년 2학기
B-ISDN and ATM (보충)
3
ATM Signaling
• UNI : User to Network Interface
• NNI : Network to Network Interface
• Different protocol in the different domain
2000년 2학기
B-ISDN and ATM (보충)
4
Virtual Path / Virtual Channel
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Connection Identifier : VPI/VCI
Physical Link : Contains multiple VPs
Virtual Path : Contains multiple VCs
Virtual Channel : Logical path between ATM endpoint
2000년 2학기
B-ISDN and ATM (보충)
5
VP and VC Switching
2000년 2학기
B-ISDN and ATM (보충)
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ATM Cell Header
PTI Payload Type Identifier(3 Bits)
- 1 bit : User/Control Data.
- 2 bit : Congestion flag.
- 3 bit : Last Cell flag
CLP Cell Loss Priority Bit
HEC Header Error Check(8 Bits)
2000년 2학기
B-ISDN and ATM (보충)
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Permanent Virtual Circuit
• Manual updates of VPI/VCI tables in network equipment
2000년 2학기
B-ISDN and ATM (보충)
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Switched Virtual Curcuit
• Setup connection using UNI/NNI signaling
2000년 2학기
B-ISDN and ATM (보충)
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ATM Reference Model
Q.2931, Q2971
SAAL
SAAL
ATM
PHY
Signaling ATM Adaptation Layer
2000년 2학기
B-ISDN and ATM (보충)
10
ATM Service Criteria
• Traffic parameters
– Peak Cell Rate(PCR), Sustainable Cell Rate(SCR)
– Maximum Burst Size(MBS), Minimum Cell Rate(MCR)
• Quality of Service
– Maximum Cell Transfer Delay(MCTD)
– Cell Delay Variation Tolerance(CDVT)
– Cell Loss Ratio(CLR)
2000년 2학기
B-ISDN and ATM (보충)
11
ATM Service Categories
2000년 2학기
B-ISDN and ATM (보충)
12
Traffic Management - I
• CAC(Connection Admission Control)
• Determine whether a connection can be progressed or not
- satisfy the traffic contract of the connection
- not disturb traffic contracts of the other connections
2000년 2학기
B-ISDN and ATM (보충)
13
Traffic Management - II
• UPC(Usage Parameter Control)
• Protect network resources from malicious as well as unintentional
misbehavior
- based on traffic contract of the connection
- action : cell discard, cell tagging
2000년 2학기
B-ISDN and ATM (보충)
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Traffic Management - III
• CLP(Cell Loss Priority) Control
• In Congestion state
- EFCI(Explicit Forward Congestion Control)
- CLP(Cell Loss Priority)
2000년 2학기
B-ISDN and ATM (보충)
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Traffic Management – IV
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CAC / Connection Management
UPC (Policing)
CLP / EFCI control
Frame Discard
Traffic Shaping
ABR Congestion Feedback
2000년 2학기
B-ISDN and ATM (보충)
16
ATM Signaling Protocol
• Point-to-Point ATM Connection(Q.2931)
2000년 2학기
B-ISDN and ATM (보충)
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Reserved VPI/VCI
Q.2971
Q.2931
2000년 2학기
B-ISDN and ATM (보충)
18
Message Structure
Information Element
Length
Protocol discriminator
Distinguish Message
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Call reference
Identify call at the local UNI
4
Message type
Identify the function of message
2
AAL parameter
4-21
ATM traffic descriptor
12-20
Broadband bearer
capability
6-7
QoS parameter
6
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2000년 2학기
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B-ISDN and ATM (보충)
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