home *** CD-ROM | disk | FTP | other *** search
- [ These Standards Updates are published after each IEEE 1003
- meeting, and are commissioned by the USENIX Association.
- See Part 1 for contact information. -mod ]
-
-
- An update on UNIX|= Standards Activities - Part 11
-
- POSIX 1003.8 Update
-
- December 18, 1988
-
- Shane P. McCarron, NAPS International
-
- 1003.8 - Networking Extensions to POSIX
-
- IEEE P1003.8's charter (not yet formally approved by IEEE,
- but pending) is to help develop an IEEE POSIX networking
- standard. This was the committee's first formal meeting,
- and it was devoted mostly to organizational matters,
- particularly on setting specific technical goals and how to
- divide the work into subcommittees.
-
- This working group has emerged out of the work done by the
- /usr/group Technical Committee's subcommittee on networking.
- Once this committee has been formally formed, the /usr/group
- networking committee will be considered to merge with the
- P1003.8 committee, and meet concurrently whenever P1003.8
- does. Ultimately, the /usr/group committee is likely to
- disband completely in favor of P1003.8.
-
- The charter ("project authorization request", or PAR) was
- reviewed briefly:
-
- SCOPE
-
- 1. Define Network Services required by portable
- applications consistent with existing and emerging
- standards such as OSI.
-
- 2. Define interfaces to the network services defined
- above, and where possible, language and protocol
- independent programming interfaces.
-
- 3. Identify the requirements for new network
- services/protocols and liason with appropriate
- standards bodies (national and international) and
- interested organizations when appropriate.
-
- __________
-
- |= UNIX is a registered trademark of AT&T in the U.S. and
- other countries.
-
-
- - 2 -
-
- PURPOSE
-
- Define and/or adopt a set of paradigms to permit the
- implementation of portable applications in a network
- environment.
-
- Areas to be addressed by this committee include:
-
- A. Interoperability between POSIX applications and non-
- POSIX applications.
-
- B. Bindings to OSI application layer services.
-
- C. Identification of language requirements not
- appropriate to applications portability, and liason
- with appropriate standards bodies to ensure that
- action is taken where appropriate.
-
- D. The evaluation and definitions, where require, of
- binding to lower layer OSI services.
-
- E. The requirements to ensure interoperability among
- POSIX-based distributed applications and services.
-
- F. Network Services profile definitions for portable
- applications (POSIX).
-
- Subcommittee Organization
-
- A poll was held to find out what the most important topics
- were as far as the group was concerned. These turned out to
- be: process to process communication, directory services,
- network management, transparent file access, and remote
- procedure call. Three main subcommittees were formed to
- look at some of these tasks. Roughly, these committees were
- "interprocess communication", "remote procedure call", and
- "transparent file access".
-
- Directory services and network management were recognized as
- important, but also as cutting across other functional
- areas. Also, it was noted that there were not in attendance
- enough people with sufficient expertise in these topics to
- form a useful body of opinion on proposals in these areas.
-
- Transaction processing was generally felt to be within the
- domain of the committee, but as a special case of remote
- procedure call. It was noted that others who were not on
- the committee may feel otherwise.
-
- The committee split up into subcommittees for a day to
- refine the definitions of the most important end products
-
-
- - 3 -
-
- identified for the committee to concentrate on.
-
- Specific Technical Goals
-
- The following is a summary of what the committee as a whole
- agreed on as a result of the input from the individual
- subcommittees.
-
- o+ Transparent File Access
-
- It was decided that the products should be client-only
- interfaces. Three products were identified:
-
- 1. Full POSIX-semantic transparent file access
- interface. This would include previous
- /usr/group DFS Committee work on DFS (distributed
- file system).
-
- 2. Administrative interface to support (1).
-
- 3. Subset-semantic transparent file access
- interfaces. This could be vendor (e.g., MS-DOS,
- Apple, etc.) or protocol (e.g., FTAM) specific.
-
- Work items identified so far include:
-
- 1. Definition of file operations
-
- 2. Liason to system administration; definitions of
- transparent file access specific system
- administrative utilities and/or interfaces
-
- 3. Liason with directory working group
-
- 4. "Appropriate approach" to the protocol invention
- problem
-
- This group expects to finish relatively quickly (6
- months or so was the estimate given), because it was
- felt that a significant amount of the work needed to
- produce standards in this area is already done by
- definition (the P1003.1 standard).
-
- o+ Remote Procedure Call:
-
- The RPC folks apparently did not define their charter
- so much as identify issues that need to be addressed.
- The following was their list of issues along with
- tentative resolutions (if any):
-
-
- - 4 -
-
- 1. Level of service
-
- 2. POSIX-to-POSIX versus POSIX-to-other (address
- POSIX-to-other)
-
- 3. Language binding (initial target: C)
-
- 4. TP support
-
- 5. Connection re-use
-
- 6. Call-back/recursion
-
- 7. Compiler language
-
- 8. Data canonicalization
-
- 9. Authentication
-
- 10. Our scope versus X.500
-
- 11. Standard suite of services need to confer with
- X3T5 on possible charter issues
-
- 12. Idempotency - execute once only guaranteed
-
- 13. Long running processes - keepalive/timeouts
- probably needed
-
- 14. Crash recovery
-
- 15. Real Time issues - no real time interface
-
- 16. Directory services
-
- 17. Multiple protocol stacks
-
- The subgroup chose not to identify the next step in the
- process (apparently meaning that they will wait for
- proposals).
-
- o+ Interprocess Communication:
-
- Four products were identified:
-
- 1. Simple Protocol-Independent Network Interface
-
- Features:
-
- * Bidirectional byte stream virtual circuits
-
-
- - 5 -
-
- * Connectionless message exchange
-
- * Read/write support
-
- * Protocol-independent naming
-
- * Asynchronous communication services
-
- * Support for both client and server processes
-
- * POSIX-to-non-POSIX support
-
- Issues:
-
- * How to resolve names in a protocol-independent
- manner?
-
- * What should the individual functions look like?
-
- 2. Simple Structured Data Network Interface
-
- Features:
-
- All of (1), with extensions for data description
- and machine-independent representation.
-
- * Description of the syntactic structure of the
- data; when you send the data, you reference the
- structure.
-
- * Not all functions from (1) may work (such as,
- read/write)
-
- Issues:
-
- * Structure alternatives: ASN.1, ...
-
- * C data structures (stub compilers)
-
- 3. Protocol-Option-Extended Network Interface
-
- Features:
-
- * Provides the ability to access protocol
- dependent options
-
- * Migration path to potential future protocols
-
- * POSIX-to-any
-
-
- - 6 -
-
- * Virtual circuits, datagrams
-
- Issues:
-
- * Limited lifespan (?)
-
- * Limited utility
-
- * Usefulness as a migration tool
-
- * Relationship to (1)
-
- 4. OSI application level interface
-
- Features:
-
- * A family of interfaces with consistent style and
- syntax which provides OSI application level
- services, e.g. FTAM, VT, ACSE, ROSE, ...
-
- Issues:
-
- * Complexity
-
- * Prioritization (which ones to focus on first)
-
- One issue that surfaced very quickly in the network IPC
- discussions was the differences and relative merits of
- sockets and XTI. Some went as far as to say that the
- differences were significant enough to guarantee
- "religious wars" over the issue, and/or make any kind
- of progress impossible in the area of product (3).
-
- Whatever the cause, a majority (8/0/3/3) of
- participants expressed interest in working on product
- (1), with products (3) and (4) having a relatively weak
- level of interest.
-
- The committee will get down to serious business at the
- next meeting (in January; 5 days). For the next
- meeting, proposals are being solicited in all areas.
- The Usenix Standards Watchdog Committee contact on this
- committee is Stephen Head. He can be reached at:
-
- Stephen Head
- Hewlett Packard
- 263 Mackintosh St.
- Fremont, CA 94539
- +1 (408) 447-2740
- smh@hpda.hp.com
- uunet!hpda!smh
-
- Volume-Number: Volume 15, Number 54
-
-