Q59584: OS/2 Days Seminar: Misc. Communications Server Questions
Article: Q59584
Product(s): Microsoft LAN Manager
Version(s): 1.0
Operating System(s):
Keyword(s):
Last Modified: 08-NOV-2001
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The information in this article applies to:
- DCA/Microsoft Communications Server, version 1.0
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SUMMARY
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OS/2 Days Developer's Conference DCA/Microsoft Communication Server
Questions and Answers Follow-Up Responses
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1. Why is user security data stored in the COM.SEC file? This makes it possible
to compromise security by taking the file to another machine. According to
the customer, this scheme matches the implementation under IBM EE
Communication Manager.
Answer
The ability to compromise APPC conversation security requires an APPC
Transaction Program (TP) to know the user ID and password when issuing an
[MC_]ALLOCATE request to initiate a conversation. Ultimately, the Comm Server
administrator must prevent unauthorized access to this file through either of
the following:
- Physical security (limiting physical access to the server machine).
- Using the LAN Manager 2.00 Local Security feature to limit unauthorized
local access to server-based files. This also prevents access to the file
when booting the server from a floppy disk.
2. How does Comm Server perform load balancing with LU pools that span multiple
connections? Does load balancing only relate to session balancing, or does
network traffic play any part in the balancing scheme?
Answer
Comm Server allows an administrator to define a pool of 3270 LUs that may span
multiple host connections. In this case, one or more Comm Server machines
(residing on the same LAN) are supporting more than one link to one or more
IBM host machines. If a Comm Server client is configured to have access to
the LU pool and a user activates a 3270 session associated with the pool, the
Comm Server client machine will randomly select a connection to use.
While this random selection method for 3270 LU load balancing is very
rudimentary under Comm Server 1.00, this will be modified under future
versions of the Comm Server to provide more reliable LU load balancing.
Factors that are being considered to improve the load balancing algorithms
include: link traffic volume, server utilization, server CPU type and clock
rate, server LAN I/O performance, and host adapter type.
3. Why isn't Comm Server set up as a LAN Manager service like SQL server?
Answer
The LAN Manager Service facility does not currently provide the amount of
detailed control required to fully implement Comm Server as a LAN Manager
service. Note that SQL Server is implemented as a single LAN Manager service,
not as multiple distributed services that require specialized managing
facilities that Comm Server supports. This idea was considered in the early
design phases of the product, and is still under consideration for future
versions of LAN Manager.
Through the "COMM" command, an effort has been made to manage Comm Server
services similar to the way the NET command works under LAN Manager. For
example:
Command Description
------- -----------
comm start <service> Starts a Comm Server service on the
local machine, where <service> is the
name of a Comm Server node or link
service. This includes the Comm Server
network access program (NAP), which is
referred to as the Comm Server
Workstation service (for clients) and
the Server service (for servers).
comm stop <service> Stops a Comm Server service on the local
machine.
comm view Displays all active Comm Server services
on the LAN (on all Comm Server server
machines).
comm manage Start the Comm Server MANAGE interface.
comm config Start the Comm Server CONFIGURATION
interface.
comm browse Start the Comm Server BROWSE interface.
4. Will Comm Server include any tools to monitor overall throughput performance
and session load? The intention here is to provide tools to help an
administrator fine-tune performance, or identify potential bottlenecks so
that software and/or hardware reconfiguration could lead to increased
performance.
Answer
The Comm Workstation/Server already supports a full range of Link Tracing,
Error and Audit logging messages, and client session monitoring/control
facilities provided by the MANAGE utility. While statistical data for
throughput analysis is not available in version 1.00, this information can be
retrieved at the IBM host using Netview. Microsoft welcomes any comments you
have regarding additional tools that that you would like to be included in
the Comm Workstation/Server products.
5. How much memory will be left over for DOS applications, once the necessary
Comm Server client software is loaded?
Answer
This subject is fairly complicated, since the Comm Server DOS client software
includes different modules that allow a customer to optimize memory usage
depending on the desired functionality at the workstation. For example, there
are three versions of the 3270 Emulator (DOS3270S, DOS3270M, DOS3270L) and
two versions of the Comm Server Network Access Program (MINNAP, COMXNAP). The
following is a brief description of these different modules:
Module Description
------ -----------
DOS3270S Supports up to five display sessions. Doesn't
support API interface. Only requires MINNAP to
interface to Comm Server. Doesn't support file
transfer options.
DOS3270M Supports up to five display sessions, including
API support. Requires COMXNAP. Supports file
transfer, but this requires extra memory.
DOS3270L Supports up to five display and printer sessions,
including API support. Requires COMXNAP. Supports
file transfer, but this requires extra memory.
MINNAP Limited-function Comm Server Network Access
Program for the DOS client. Only supports
DOS3270S. Doesn't support the DOS client APIs.
COMXNAP Full-function Comm Server Network Access Program
for the DOS client. Includes support for APIs and
3270 emulators.
The following are PRELIMINARY memory usage estimates for different scenarios.
Note that these estimates do not include potential memory savings by using
64K of expanded memory. DOS LAN Manager 2.00 numbers reflect debug version
memory use, which will decrease when the final version is shipped. Also,
these estimates assume that the DOS client is only attached to one LAN, and
is using Microsoft's NETBEUI protocol over Token Ring.
Estimated Base Memory Requirements
----------------------------------
DOS Operating System .................... 50K (Minimum DOS 3.30)
Enhanced DOS LAN Manager 2.00 ............ 60K *
DOS LAN Manager Transport & MAC Driver ... 36K
----
Estimated Base Memory Requirements = 146K
* Preliminary version, using minimum settings and without use
of high memory.
Memory Usage Under Different Scenarios
--------------------------------------
a. One DOS 3270 display emulation session, no API support:
Estimated Base Memory Requirements ....... 146K
MINNAP (limited-function NAP) ............ 27K
DOS3270S (small emulator) ................ 103K
----
Total = 276K
b. One DOS 3270 display emulation session with API support:
Estimated Base Memory Requirements ....... 146K
COMXNAP (full-function NAP) .............. 40K
DOS3270M (medium emulator) ............... 121K
----
Total = 307K
c. Three DOS 3270 display emulation sessions and two printer sessions,
including API support and one 3270 Model 2 file transfer session active:
Estimated Base Memory Requirements ....... 146K
COMXNAP (full-function NAP) .............. 40K
DOS3270L (large emulator) ................ 263K
One file transfer session ................ 47K
----
Total = 493K
d. APPC API support, with no 3270 functionality:
Estimated Base Memory Requirements ....... 146K
COMXNAP (full-function NAP) .............. 40K
----
Total = 186K
6. Comm Server 1.10: Will future LU0 support include support for a DOS client?
Answer
This is recognized as a valuable extension of the Comm Server/Workstation
product for possible inclusion in a future release. While LU0 support has not
been formally added to the list of version 1.10 enhancements, Microsoft is
planning support for both high-level and low-level LU0 interfaces (known as
LUA in the IBM EE 1.2 product) for DOS and OS/2 clients.
7. Comm Server 1.10: Will the 3270 Presentation Manager (PM) client include
clipboard (cut-and-paste) capability?
Answer
Yes, this is included in Comm Server/Workstation version 1.10.
8. Comm Server 1.10: Will LAT support be included? This is required to support
Ethernet communication with DEC/VAX environments.
Answer
This is recognized as a valuable extension of the Comm Server/Workstation
product for possible inclusion in a future release. However, LAT support has
not been formally added to the list of version 1.10 enhancements.
9. Comm Server 1.10: Will IBM 5250 terminals be supported?
Answer
This is recognized as a valuable extension of the Comm Server/Workstation
product for possible inclusion in a future release. However, IBM 5250 support
has not been formally added to the list of 1.10 enhancements.
10. Comm Server 1.10: Will DEC VT100 Async Emulation be supported?
Answer
Yes, Comm Server/Workstation version 1.10 will include asynchronous terminal
emulation support for the following terminal types:
DEC VT52, VT100, VT200 and VT220
IBM 3101/20 and 3101/40
TTY Emulation
11. What releases of OS/2, LAN Manager, and SQL Server are compatible with each
other?
Answer
Please note the product compatibility matrix below. This matrix identifies
different releases of OS/2, LAN Manager, SQL, and Comm Server version
compatibilities. Additional information is provided below for certain
product versions. With the exception of the "NDK" and "SDK" programs (which
have been discontinued by Microsoft), these products are only available
through OEM vendors.
LAN SQL DCA/MS DCA/MS Comm
Manager Server Comm Server Workstation
------- ------ ----------- -----------
OS/2 1.00 SA * SQL NDK, SQL NDK, - -
1.00, 1.00
SDK 1.07,
OS/2 1.10 1.00, 1.00 - -
SDK 1.07
OS/2 1.10 SA * 1.01, 1.01+ 1.00 - -
IBM OS/2 1.20 SE (1) - - -
OS/2 1.20 (2) 2.00 (3) (4) 1.00 (5) 1.00 (6)
* Standard releases of OS/2 1.00 and 1.10 did not support the anticipated
capacity requirements of the LAN Manager server and SQL database software
products at the server. To overcome some of these limitations, the LAN
Manager/SQL releases include a special version of the OS/2 kernel referred
to as "OS/2 Server Adaptation" (SA) for OS/2 versions 1.00 and 1.10. The
"Server Adaptation" releases were discontinued after the LAN Manager 1.01
release, since OS/2 file system capacity has been significantly enhanced in
OS/2 versions 1.20 and later.
LAN Manager/SQL Releases
------------------------
Release Description
------- -----------
SQL NDK Microsoft's Network Development Kit (NDK) release
for SQL Server. This release included OS/2 1.00
Server Adaptation, LAN Manager 1.00, and an SQL
Server Beta release. The NDK program has been
discontinued by Microsoft.
SDK 1.07 Microsoft's Software Development Kit release for
LAN Manager. This release included OS/2 1.00
Server Adaptation and LAN Manager 1.00. The SDK
program has been discontinued by Microsoft.
SQL 1.00 The official SQL Server 1.00 retail version was
released by Ashton-Tate, which was newer than the
SQL Beta version distributed by Microsoft with the
SQL NDK.
LM 1.00 Microsoft LAN Manager 1.00 release to OEM
customers only. This version was also included in
Microsoft's SDK 1.07 package for software
developers.
LM 1.01 Microsoft LAN Manager 1.01 release to OEM
customers only. This release included OS/2 1.10
Server Adaptation and LAN Manager 1.01.
LM 1.01+ Microsoft LAN Manager 1.01 update release to OEM
customers only. This release included some bug
fixes to the LM 1.01 release.
a. IBM OS/2 1.2 Standard Edition does not provide the necessary support for
any version of LAN Manager. Since OS/2 1.2 includes support for
installable file systems (IFS), LAN Manager 1.0x versions will not operate
on this version. An upcoming version of LAN Manager (version 2.00), which
is implemented as an IFS, is designed to run on an upcoming version OS/2
1.2, but not earlier versions.
b. Microsoft has not completed certification of this product (as of March 14,
1990), so it is not available through OEM vendors. OS/2 1.2 Standard
Edition is available from IBM, corresponding to the most recent Corrective
Service Distribution (CSD) release.
c. Microsoft has not released LAN Manager 2.00 to OEM customers (as of March
14, 1990). LAN Manager 2.00 will require the version of OS/2 1.2 referred
to in Item 2 above.
d. This new version of SQL Server, which will be available through
Ashton-Tate, has not been released yet (as of March 14, 1990). This
release will require the version of OS/2 1.2 referred to in Item 2 above
and LAN Manager 2.00 referred to in Item 3 above.
e. Microsoft and DCA have not completed certification of this product (as of
March 14, 1990), so it is not available through DCA or OEM vendors. Comm
Server 1.00 requires LAN Manager version 2.00.
f. Microsoft and DCA have not completed certification of this product (as of
March 14, 1990) so it is not available through DCA or OEM vendors. Comm
Workstation 1.00 requires OS/2 1.20, but not LAN Manager.
Additional query words: 1.00 prodcs
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Keywords :
Technology : _IKkbbogus kbSNAServSearch kbDCAMSCommServ
Version : :1.0
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