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Telecom Signaling Networks and Service Forum January 18, 2006 Amsterdam. I am Adrian Georgescu. I work for AG Projects, which is developing solutions for convergence of the Telecom and Internet. The opinions expressed in this presentation belong to myself, my company and most of my friends.
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Telecom Signaling Networks and Service Forum January 18, 2006 Amsterdam
I work for AG Projects, which is developing solutions for convergence of the Telecom and Internet
The opinions expressed in this presentation belong to myself, my company and most of my friends
Internet is a dumb network, the services (applications) are performed at the edge
Dumb means: Internet role is simply to locate and route packets to the destination IP address
Because allowing innovation is what made Internet a success!
Ethernet is the most successful network transport protocol on Earth despite the fact that it does not have any QoS management built-in!
Because it could be upgraded to 10, 100, 1000, 10000 Mbit/s without having to change a bit of the routing protocol or the applications on top of it!
PSTN is a “guaranteed” transport medium with switched circuits (paths)
The question today is: How do I guarantee a voice call will work with the expectation that it will not fail or it provides the quality we use to experience from PSTN?
- We build IMS, we apply telco logic on top of Internet - We build and deploy bandwidth management systems, Pocket Cable, MPLS and others - Buy our own technology, it has QoS just stick with our proprietary stuff! The answers you get today from you vendors:
Unfortunately, these answers do not address the problem They address only your pocket!
50 millions users of Skype proved that users are prepared to trade all PSTN “guarantees” with a new Internet application
Lets try to find some real solutions which are also cost effective!
Internet has two measurable performance parameters: 1. Round-trip time (RTT) Keep it below 200ms 2. Packet loss (%) Keep it under 0.5%
And two ways to deliver data: 1. UDP protocol (no guarantee of delivery but good for RT) 2. TCP protocol (guarantee of the delivery, very good for signaling bad for RT)
And all these are confined into a bandwidth “force-field”
Is cheaper to increase the bandwidth than to build systems that managed the lack of it
Do you imagine today a QoS management system for old dial-up Internet instead of going to broadband?
Building QoS management systems is difficult, non-interoperable and expensive By the time such systems are deployed the bandwidth has doubled or more already, and you are stuck with a solution build for the past
Internet performance has been improved dramatically in the last 10 years Source: http://www.slac.stanford.edu/xorg/icfa/icfa-net-paper-jan05/
Complex systems cannot provide a solution for lack of bandwidth, any system added in the chain will put strains on QoS as well
Overall ETSI TISPAN IMS Architecture – all subsystems Rf /Ro Ut Rf /Ro Charging Ut Application Servers Functions Sh Rf /Ro ISC Dh UPSF Iw SLF Cx IWF Dx Ib P3 IMS / PSTN Simulation PSTN Emulation (R2) Mw Mw/Mk/Mm IBCF Ic I/S - CSCF Mk Mi AGCF P2 Mk BGCF Mw Mr Mj Gq ' Mg e2 SGF P - CSCF MGCF MRFC Ie Other IP Networks P1 Gq ' Gq ' Network Gm SPDF PSTN/ISDN SPDF Attachment Resource & Admission Control Resource & Admission Control Mp Mn Subsystem A-RACF e4 MG Re Ia MRFP T - MGF I - BGF UE BGF RCEF IP Transport (Access and Core) CNG -
To improve the quality of service experienced by your end-users you can follow common-sense best practices:
1. In the core, monitor the network to avoid congestion, network loads of 30%-40% are considered adequate for quality of service and for congestion avoidance 2. At the edge (last mile), provision two paths from the IAD to the first IP switch.This way RT applications will not collide with non-RT applications. Invest in last mile bandwidth upgrades instead of QoS management systems for it 3. In case of packet-loss use smart applications that automatically fail-over to other hosting center 4. Don’t tunnel signaling and media to home network (like IMS does), use geographical distribution of resources 5. Use Internet codecs like iLBC or Speex instead of G.7xx
QoS systems do not create bandwidth! Remember that:
This presentation is available at: http://ag-projects.com
Thank you, Adrian Georgescu ag@ag-projects.com