Download QTP_Transport

QTP as Transaction Transport Layer
High-capacity, connection-oriented transaction transport
[email protected]
(604) 451-1567
Connectivity . . . guaranteed.
Introduction
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Who is INETCO?
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Software vendor linking institutions
with terminals
See www.inetco.com
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Our perspective
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Financial/retail vertical market
Financial TP is often “Most mission
critical application”
We make new elements evolving
into a system communicate with
what is already there.
Normally we work in all layers below
ISO8583 or equivalent message.
Connectivity . . . guaranteed.
Why are we here?
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Joint authors of QTP - transport
protocol for POS transactions over
IP.
SOAP/HTTP emphasizes clientweb-server interaction. QTP
addresses concentration points
(back-end).
Scope
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Deal with communication issues, not
use of RPC vs. Message API.
Typical POS Architecture
POS
Terminals
(1000s to 100ks)
Network
Access
Controllers
or FEP
X.25/Dial
Access
Network
Institutions
EFT TPs
SNA/X.25/FR
Access
Network
Message (ISO8583 or other)
Message
Visa, TPDU, CLNP, None
Visa, TPDU, CLNP, TPDU
HDLC, X.25, Async
X.25, FR, IP
Connectivity . . . guaranteed.
Transport Layer Requirements
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Performance
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Restrict by source access network
address
Restrict by source transport-layer
address
Restrict RAS - INAC communication
Provide legal intercept
Transaction delivery
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Either non-reliable delivery, or
Reliable delivery with end-to-end
data acknowledgements
Connectivity . . . guaranteed.
Access Network independence
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Security
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Fast connection processing
High availability
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Transport layer independence
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X.25, FR, Dialup, ...
TCP or UDP, FR, other
Scaling
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>100k transaction terminals
>100 financial institutions
Initial peak ~500 TPS with scalable
growth
IP-oriented Architecture
POS
Terminals
INAC
clusters
Remote
Access
Servers
X.25/Dial
Access
Network
IP
Network
Institution
EFT TPs
SNA/X.25/FR
Access
Network
Message (ISO8583 or other)
Message (as is)
Message (as is)
Visa, TPDU, CLNP, None
Transport (as is)
Host transport
HDLC, X.25, Async
QTP
X.25, SNA, FR
UDP/IP
Connectivity . . . guaranteed.
QTP Overview
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Status
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Released as Internet Draft:
 draft-cornish-qtp-01.txt
First applications in production
Incorporated by other vendors.
Opensource version available for
draft-cornish-qtp-00.txt
Characteristics
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Lightweight connection multiplexing
Symmetric
Individual message acks
Status for source routing decisions.
Independent of lower-level transport
Attribute/Value based
Extensible
Connectivity . . . guaranteed.
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Header
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Version
Msg ID, Msg ID Ack, Priority flags
Length
Src / Dest Logical Channel Number
Optional Msg ID, Msg ID Ack values
Attributes for
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Session establishment
Data transfer
Session management
Element status
Statistical information
Vendor extensions
QTP Attributes
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Session Establishment
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Called / Calling party addresses
Called / Calling party subaddresses
Address family (E.164, X.121, …)
Profile, speed, idle timeout
Max message
Protocol identifier
Customer group identifier
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Session Management
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Element Status
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Data Transfer
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Data / Block data
Management info
Q Data / Call Data
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Flow control state (Available, Congested)
Station status (Primary, Secondary, …)
Ping
Call state
Statistical Information
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Connectivity . . . guaranteed.
Cause (Normal, various QTP causes)
Remote cause (Normal, various Access
causes)
Messages received / sent
Unacked messages
Time since last restart
Closing Comments
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QTP not a fit for client side, unless client is really a gateway / proxy for
many transaction generators.
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Primary incentive for choosing QTP today is scaling beyond TCP
session limits. QTP addresses concentrated connection-oriented
transactions.
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May be future interest in SOAP over QTP.
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Would require split into SOAP encapsulation and SOAP over HTTP specs.
As transaction concentration increases, so does emphasis on security,
reliability, and performance.
Connectivity . . . guaranteed.