1. 1 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies The Need for A Network Resource Status Service IMIC Workshop 1999 Boston University John Zinky jzinky@bbn.com BBN Technologies GTE www.dist-systems.bbn.com/tech/QuO August 30, 1999 QuO

2. 2 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies Specifying QoS Parameters is a Familiar Concern To Even the Youngest User Size of Picture Sample Rate of Sound User-Level QoS Mbytes of Movie File Type of Movie Player Access Speed of ISP CPU/Memory System-Level Requirements

3. 3 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies Distributed Objects with QoS Extensions is a Powerful Abstraction Layer on Which to Build Applications Ethernet TCP/IP QoS ATM RSVP Multicast Collaborative Planning WorkFlow Simulation Applications for geographically dispersed, heterogeneous environments Distributed Objects are the first abstraction layer that unifies CPU, storage, and communications This interface needs to be hidden from applications It is too complicated It is changing too quickly CORBA + QuO

4. 4 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies Trading-Off Bandwidth, CPU and Storage is the Key to Creating QoS Aware Applications. Storage is moving into the edge network The Bandwidth bottleneck is at the edge of the network Java Applets move CPU away from the servers to the client The backbone network is getting faster, but dumber ISP ServerClient Web Farm Web Node

5. 5 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies QoS is well-controlled for some location of Client and Object QoS is unruly across the network How can we resolve this? The QoS Problem: Who is in Charge of Managing QOS ClientObject ClientObject Network ClientObject ClientObject

6. 6 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies Simple Client/Server-Base CORBA Implementation Does Not Manage QoS in the Network ClientNetwork Server Application Developer Middleware Developer Logical Method Call Client ORB Proxy COTS ORB Object ORB Proxy COTS ORB Network

7. 7 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies QuO Adds QoS Control and Measurement Into the CORBA Remote Method Call ClientNetworkServer Application Developer Qosketeer Mechanism Developer Logical Method Call Client Delegate ORB Proxy Specialized ORB Contract SysCond Object Delegate ORB Proxy Specialized ORB Contract Network Mechanism/Property Manager SysCond

8. 8 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies Remote Object Network Server ORB Client ORB QuO Delegate Client QuO Delegate IDL QDL QuO Clients Connect to CORBA Objects using Functional and Quality Interfaces A QuO Connection logically moves the object into the client’s address space The QuO Connection integrates the individual QoS agreements for the Network, Client, and Server, by using a contract Quality Interface Description Language Defines the Functional Interface Quality Description Languages Define the System Interface QuO helps spread the object’s functionality to the most desirable location; extending the strict Client-Server implementation of the object The Client sees NO change in the functional interface, I.e. the language bindings are the same Functional

9. 9 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies CMU REMOS is an Example of Network Configuration and Status Dissemination Service

10. 10 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies QuO Instrumentation Collects Resource Status and Measures Delivered QoS Resource Status Collect Translate Integrate Infer Disseminate Expected QoS Delegate Client Object Measured QoS Probes QuO Gateway QuO Gateway Probes Correlate Probes Piggybacked Measurements

11. 11 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies Applications Need to be Aware of Available Resources Configuration Information (Query-based) The expected Capacity between two IP addresses The expected MIP of the Client and Server computers Possible Caches at Client, Servers and Proxies Status Information (Subscription-based) Number Greedy Flow over bootleneck link Load Average of Hosts Available cache size

12. 12 8/99 IMIC Workshop 6/22/2015 New Network ServicesJohn Zinky BBN Technologies Conclusion: Resource Awareness is a Missing Service that should be offered by Networks Distributed Objects infrastructure is the place to make trade-offs between Bandwidth, CPU, Storage. A Resource Configuration and Status Service is needed to make these trade-offs The Network infrastructure must be involved with creating this service. Two levels of service are needed –Query-based to get Configuration –Subscription-based to get Status The service should be as Ubiquitous as DNS –DNS is Administrative, not physical