COMM-PRO
X.25 Host NAS
Network Access Support
(HNAS) NPSI Emulation
for Z/OS, OS/390 and MVS/ESA
TCP/IP Host to Cisco and Other XOT Enabled
Routers as well as IBM
XTP Router Solutions Overview
HNAS Overview Presentation File
As a convention in this document, the term router
is used to refer to the family of Cisco network routers (26nn, 36nn, 45nn, 7nnn,
etc.) or IBM network routers (2210, 2212, 2216).
X.25 Host Network Access Support for
Z/OS, OS/390 and MVS/ESA
Comm-Pro's X.25 Host Network Access Support (HNAS) for Z/OS, OS/390
and MVS/ESA program products
solves a strategic problem that exists in the communications
world today. Many organizations are now consolidating their SNA,
X.25 and TCP/IP networks in order to optimize system operations,
reduce costs, reduce system downtime and increase overall
productivity. Comm-Pro's HNAS product
helps to accomplish these objectives in the following ways:
- Provides support for X.25 connectivity over router based
networks using Cisco's X.25 over TCP/IP (XOT) or IBM's X.25 through TCP/IP (XTP) transport protocols.
- Provides support for native TTY compatible ASCII devices
using the Interactive Terminal Interface (ITI) protocol
over XOT or XTP.
- Provides support for Cisco's translate IP to XOT feature allowing inbound telnet
sessions to be protocol converted into ITI, PCNE or PAD sessions. This
allows native ASCII telnet devices (non-TN3270) to access NPSI host
application as well as the HNAS remote console access support.
- Provides host emulation of X.25 NPSI functions thus
eliminating the need for Front End Processors when they
are used solely for NPSI.
- Provides the suite of NPSI interfaces for non-SNA
resources:
- PCNE - Protocol Conversion for Non-SNA Equipment
allows ITI devices to access VTAM applications as SNA
3767 LUT1 devices. From the host's viewpoint, there
is no distinction between real LUT1 terminals and
those that are simulated via PCNE. Terminal
connections that require PCNE services use Logical
Line Control Type 0 (LLC0).
- IPAD - Integrated Packet Assembler/Disassembler
provides host resident X.29 services for ITI devices
in addition to PCNE services. Terminal connections
that require IPAD services use Logical Line Control
Type 5 (LLC5).
- XPAD - Transparent Packet Assembler/Disassembler allows host
applications to control PAD parameters
via an action byte in the data stream. Terminal
connections that require XPAD services use Logical
Line Control Type 5 (LLC5).
- GATE - Generalized Access Transport Extension allows
host applications to control X.25 virtual circuit
session establishment and disconnect using a control
LU session and data transfer using a separate data LU
session. Terminal connections that require GATE
services use Logical Line Control Type 4 (LLC4).
- GATEFC - GATE Fast Connect allows host applications
to control X.25 virtual circuit session
establishment, disconnect and data transfer using a
single LU session. Terminal connections that require
GATEFC services use Logical Line Control Type 4
(LLC4).
- Provides support for GATE, GATE-FC, PCNE, IPAD and XPAD host-to-host
application connectivity over TCP/IP based networks with no requirement for
Cisco's X.25 over TCP/IP (XOT) or IBM's X.25 through TCP/IP (XTP) protocols
defined in the routers. When HNAS is installed at each location end
point, the hosts can communicate with each other over an IP network without
any X.25 facilities or Cisco XOT routers. GATE or PCNE file transfer
applications in each host can communicate with each other via the HNAS-XOT
to HNAS-XOT connection. With this technique, packet and window sizes
can be adjusted to optimize network performance, reduce CPU utilization and
eliminate router serial X.25 link interfaces.
- Provides support for Qualified Logical Link Control (QLLC/LLC3) over
XOT. Native SNA support for PU Type 1, LU Type 2 over QLLC. This support is
new for HNAS V2R2M0 and eliminates the previous requirement to employ DLSW
at the host location. DLSW line attachment with XOT encapsulation is
required at the remote location unless HNAS XOT QLLC services are employed
in Host-to-Host environments.
In the HNAS V2R3M0 release, QLLC Callout support is available with a variety
of methods to generate the SVC (switched virtual circuit) callout
connection.
- Provides transparent access to most NPSI host
applications - no modifications are required to existing
host software. HNAS doesn't currently support DATE or SNI.
- Is fully year 2000 compliant.
Network Migration
Due to the proliferation of 'legacy' host applications which
require X.25 connectivity, many Z/OS, OS/390 and MVS environments still rely
on traditional Front End Processors and the NCP and NPSI
program products. The family of Cisco and/or IBM routers offer a partial solution to bridging
X.25 and TCP/IP based networks.
- For Cisco and/or IBM routers, native SNA connectivity using the
Qualified Logical Link Control (QLLC) X.25 transport protocol allows DTE to DTE and DTE to host access.
- For Cisco and/or IBM routers, non-SNA connectivity using the
X.25 over TCP/IP (XOT or XTP) encapsulation protocol allows DTE to DTE but not DTE to host access
without the use of additional non-native equipment.
The missing piece in the network migration scenario
is support for a router to host connection which
eliminates the need for a FEP but which incorporates all
the NPSI functions for non-SNA equipment
(PCNE, IPAD, XPAD, GATE and GATEFC).
The Solution
Comm-Pro's mainframe resident HNAS program product provides
the missing interfaces precisely where the NPSI application executes.
Using the XOT or XTP transport protocol within an Z/OS, OS/390 or MVS
environment to channel attached or LAN attached Cisco
and/or IBM routers, HNAS eliminates the need for Front End Processors and
their associated NCP and NPSI software licenses (see figure 3 below).
______________________________________________________________________
| |
| With X.25 HostNAS |
| |
| TCP/IP X.25 |
| HOST NETWORK ROUTER NETWORK ITI PAD |
| _________________ _____________ |
| | | | | | XTP|XOT | | | | ITI | | |
| | <-> <-> <-> |<--------->| <-----> |<---------->| |<-->| |
| | | | | | | | | I | | | | |
| | C | V | H | T | | X | | T | | |
| | I | T | N | C | | T | | I | | |
| | C | A | A | P | | P | | | | |
| | S | M | S | I | | / | | P | ITI DEVICE | |
| | | | | P | | X | | A | _______ | |
| | | | | | | O | | D | | | | |
| | | | | | | T | | | | |<-->| |
| | | | | | | | | | | | |
| |
| Non-SNA device traffic is carried across the X.25 network in |
| ITI packets. IBM or Cisco routers encapsulate the ITI packets |
| in XTP or XOT before they are passed to the TCP/IP network. |
| The peer TCP/IP companion in this case is a host TCP/IP stack |
| with an X.25 Host NAS component. Together, they take the role |
| of peer router. The XTP or XOT data is passed to X.25 Host |
| NAS from the TCP/IP stack. X.25 Host NAS de-encapsulates the |
| XTP or XOT packets then passes LUT1 SNA data on to VTAM. |
| |
Figure 3: Non-SNA traffic in a hybrid X.25-TCP/IP network
with HNAS
Host NAS can also be used in environments with host-to-host (application to
application) sessions without the requirement of XOT or XTP router protocol
conversion when HNAS is used at both host end points. The HNAS XOT host
messages are transported across the TCPIP network without any physical X.25
service requirements in the network or routers. HNAS eliminates the need for Front End Processors
(their associated NCP and NPSI software licenses), physical X.25 networks or
services and routers with XOT or XTP protocol requirements (see
figure
4 below).
______________________________________________________________________
| |
| With X.25 HostNAS host-to-host Support |
| |
| TCP/IP |
| HOST A NETWORK HOST B |
| _________________ ________________ |
| | | | | | IP | | | | | |
| | <-> <-> <-> |<--------->| <-> <-> <-> | |
| | | | | | | | | | | |
| | C | V | H | T | L | T | H | V | C | |
| | I | T | N | C | WAN | C | N | T | I | |
| | C | A | A | P | N | P | A | A | C | |
| | S | M | S | I | | I | S | M | S | |
| | | | / | P | | P | / | | | |
| | | | X | | | | X | | | |
| | | | O | | | | O | | | |
| | | | T | | | | T | | | |
| |
| Host application traffic is encapsulated into XOT packets then |
| delivered to the TCP/IP network for routing to the destination |
| host. Cisco XOT or IBM XOT protocol services are not required |
| in the routers because there are no physical X.25 interfaces |
| or service requirements in the network. |
| |
Figure 4: Non-SNA traffic across a TCP/IP network with host-to-host
HNAS-XOT support
Objectives and Benefits of Comm-Pro’s HNAS product include:
- A seamless backbone network. Native TCP/IP traffic is
delivered directly to the host mainframe.
- Simplified management of resources. The Simple Network
Management Protocol (SNMP), which is native to TCP/IP,
can be used to manage and monitor XOT or XTP router
sessions.
- Elimination of Front End Processors. HNAS
runs on the mainframe obviating the need for
FEPs that are used for NPSI only in order to support
native NPSI functions. Cisco and/or IBM routers, when
used with HNAS, provide VTAM
connectivity for SNA and non-SNA devices.
- Improved network resource scalability. Use of the cost
effective family of Cisco and/or IBM routers as FEP
replacements provide scalability that can not easily be
matched using Front End Processors.
- Redundant routers reduce network downtime. Due to their
modest cost, multiple routers can be used to provide
alternate paths to the same target DTE.
- Elimination of NCP and NPSI software licenses. No FEPs
means no FEP software or hardware maintenance fee's.
- Simplified configuration procedure. No Sysgen is required
to generate HNAS resources. A
small configuration data file is all that is
necessary. This file is interpreted by HNAS
when it initializes. All required control
blocks are created dynamically based on information
supplied in the configuration data file.
- Better use of staffing resources. Data center personnel
no longer have to support and maintain complex NCP and
NPSI Sysgens.
- More bandwidth for less money. Perhaps the most
significant aspect of the HNAS
to IBM router implementation is the fact that Levels 1, 2
and 3 of the X.25 protocol stack are managed by the IBM
routers themselves. This means that all flow control and
packet sequencing is done locally by the routers so that
only data packets and session control packets need
traverse the TCP/IP network. Cisco routers provide Levels
1 and 2 of the X.25 protocol stack and even though
HNAS must provide Level 3 support, it still
can represent a significant savings in host CPU resources.
This increases real bandwidth and minimizes the amount of
work the HNAS must do to
maintain an X.25 virtual circuit session (We recommend that XOT users
increase the session level packet size and window size to further improve
data delivery performance). Other X.25 host
to router implementations require the host software to
perform the X.25 Level 2 and 3 protocol. These
implementations consume far greater host CPU cycles.
- Simplified troubleshooting. Diagnostic capabilities are
provided by HNAS in addition to
standard GTF facilities. HNAS includes
extensive trace and error reporting facilities as well as
a console subsystem. The console can be accessed locally
via the host WTOR or MODIFY interface, by line mode devices in
the local router or remotely using ITI PAD or telnet access.
Please refer to the Console Subsystem area for router
access or remote console access information.
Features Provided by Comm-Pro’s HNAS
Product include:
- Support for Cisco's XOT and IBM's XTP transport
protocols. No changes are required to the X.25 network
and complete transparency is maintained between remote
DTEs and host applications. Routers can be directly
attached to the mainframe channel or can be on a LAN
shared by multiple routers and hosts.
- Support of standard NPSI non-SNA interfaces. PCNE, IPAD,
XPAD, GATE and GATEFC sessions access host applications
as LUT1 resources. No changes are required to the host
applications.
- Callout support for non-GATE sessions. PCNE, IPAD and
XPAD SVC connections can be initiated by
HNAS. HNAS
simulates the NPSI CONNOUT function for switched LU
resources without a Switched Major Node component.
The HNAS configuration allows remote DTE
addresses to be specified so that HNAS can initiate SVC
sessions when a BIND is issued to the associated SLU resources. A BIND,
rather than a CONNOUT, causes an XOT or XTP Call Request packet to be
transferred to the remote DTE. This feature is important for host-to-host
applications.
- Backup Router Support for LLC0/5 Callout introduced in HNAS 230.
When an LLC0/5 callout fails (timeout or clear) HNAS will try to find an
alternate path for the call by continuing to process the DTE address from
the SVC0/5 entry in the RTEOUT= list. If another match in RTEOUT= is located
the call will be tried on the associated router. After the entire RTEOUT=
list has been processed the process is repeated for the second and third DTE
address in the SVC0/5 entry (if present).
- Selectable SLU support for non-GATE sessions. PCNE, IPAD
and XPAD SVC connections can be mapped to unique SLUs
based on their remote DTE addresses. The HNAS configuration allows remote DTE
addresses to be specified so that HNAS
can associate the addresses with specific SLU resources.
This guarantees that a host application will always know
'who' a remote DTE is by its unique SLU name. This
feature is important for security conscious applications
like CICS.
- Simulated MCH support for GATE sessions. The HNAS configuration allows the X.25
multi-channel links (MCHs) on IBM routers to be
individually addressable. This means that a host CTCP
application's view of the X.25 network does not have to
change. HNAS, together with the
IBM routers, become an 'extension chord' to the X.25
network.
- Audit logging of connections. XTP and XOT connection
initiation and termination requests are noted in a user
defined log file.
- Elimination of NCP/NPSI Sysgens. A small configuration data file and a VTAM application definition file
are all that are required for HNAS
operation. An HNAS
Configuration Data File (CDF) is used to describe the
router network. The CDF is interpreted by HNAS when it is started. An
HNAS Application Major Node File (AMNF)
supplies application SLU names. The AMNF provides a
function similar to the NPSI Switched Major Node File and
is used for routing ITI calls.
- Console subsystem. HNAS provides
a console interface that can be accessed locally via a standard host WTOR/MODIFY interface, or
remotely via an ITI pad or Cisco router XOT ITI connection. The user selectable X.25 ITI
session can originate using a remote pad, telnet to Cisco pad function
(translate) or local Cisco aux or con router pad session support.
The remote console access is password protected. The console subsystem provides a mechanism to
start, stop and display trace information, start, stop
and display statistics information, display and alter HNAS storage areas, display router state
information, display 'simulated' NPSI Multi-Channel Link
(MCH), Virtual Circuit (VC) and Logical Unit (LU) state
information and monitor HNAS resource
utilization.
- Internal tracing facilities. Provides an extensive
tracing capability that allows data at the TCP/IP, XTP,
XOT, VC and LU levels to be selectively logged in a
memory resident trace table. Trace entries can also be
written to the HNAS log file.
Tracing can be started automatically when HNAS
activates using EXEC parameters or can
be started dynamically via console commands.
- Customization support based on individual user
requirements. Comm-Pro can modify the functions provided
by HNAS to suit an
installation's specific requirements. Although the 'off
the shelf' version of HNAS will
be sufficient for most users, some may choose to add
non-standard or user-defined functions. Comm-Pro has
always had a policy of providing custom modifications on
a time and expenses basis.
Following is a list of applications that have been
successfully tested with HNAS:
- ARBITER (PAD) from TANGRAM.
- Artemis and Multitran with the Integrated PAD (IPAD) function.
- btx Online Banking System (GATE, the CTCP was written by IBM while the
applications were added individually by the various banking groups).
- CECA (SICA, SIAMI and TAF) applications from Spanish Savings Bank
Federation.
- CICS, IMS and TSO (PAD and PCNE) from IBM.
- CICS (GATE FC) from IBM.
- CICS (SNA QLLC) with PU Type 2.0 for IBM 3174, IBM 4700 or IBM
PERSONAL COMMUNICATIONS/3270.
- Connect Express (GATE and PCNE) alias TOM from STERLING COMMERCE.
- Connex supporting POS (GATEFC) and ATM transactions from eFunds.
- CSFI and CSFI/VCP IBM with the GATE function from IBM.
- Datafono ISARX25 support now available under HNAS 230.c and HNAS 240.
EDITRAN CICS (GATE) function from INDRA.
- EDITRAN IMS (GATE) function from INDRA - see following ISARX25 entry.
- IMS, CICS and TSO (PAD and PCNE) from IBM.
- IMS (PCNE) and CICS (GATE FC) from IBM.
- ISARX25 3745 NPSI replacement product in Spain can be replaced using HNAS
in EDITRAN (GATE) environments. See Application and Product Notes section
for additional information. Click here for additional information link.
- Multitran and Artemis with the Integrated PAD (IPAD) function.
- ONGUM (PCNE) file transfer function.
- OSI/FTAM (GATE) from IBM.
Pelican (now Interpel)
- RVS File Transfer System (GATE) from VW - GEDAS.
- SABRE into IMS (PCNE) from SABRE INC.
- SIMVTAM (SIM3270/SIMPC) from Simware.
- STX (Unicenter CA-STX ) CICS Callout (PAD) Support.
- SWIFT FIN into IMS (PCNE) from SWIFT and KEYSTONE SYSTEMS.
- TDS-ES and TDSLink agents for S/390 monitoring from
Telecoms Data Systems.
- VIRTEL (GATE) from SYSPERTEC.
- XFB.Monitor (CFT et Inter.Pel) from Axway a Sopra Group Company
(GATE, PCNE and PAD)
System Requirements
- HNAS runs in Z/OS, OS/390 (MVS open
edition) or MVS/ESA environments. Z/OS V1R1 thru V1R13 (Z/OS
V2Rn), OS/390 V1R1 or
later, MVS/ESA V4R3 or later are
supported. OS/390 V2R5 and earlier releases run under the IUCV
interface while OS/390 V2R8 and later run under the MAPI interface.
Please refer to the following link for up-to-date information regarding HNAS
and Z/OS level support activity: Product Notices (Important information) .
- HNAS requires the facilities
provided by the host TCP/IP stack in addition to VTAM to
establish and maintain sessions between X.25 DTEs and
host applications.
- HNAS establishes its presence
to the host TCP/IP stack and VTAM when it is started. A
TCP/IP Configuration Data File (CDF) is required to
describe the router network. A VTAM Application Major
Node File (AMNF) is required to define the Logical Units
that will be used for host application access. IBM's
TCPIP V2R2M1 or later and VTAM V3R4 or later are
required.
- HNAS is primarily distributed via our FTP Server access
(edistribution), although E-mail attachment or Compact Disc's
(CDROM) are available depending upon customer requirements. The current product
distribution contains a single HNAS.ZIP (non-SMP/E) or LNS.ZIP (SMP/E) achieve file (with all required
installation files included) or as a collection of
stream files created using the TSO XMIT transmit command (files
are compressed unloaded partitioned datasets) while older distribution
methods provided macro library and object module files that were Link Edited
(Z/OS, OS/390 and MVS) at product installation time to
create the HNAS load module. SMP/E support is optional and
not required for HNAS
product installation.
Router Requirements
- HNAS supports Cisco XOT enabled routers and
IBM XTP enabled router . Interface types, memory requirements and
IOS (software) levels are dependent upon configuration size as well as
resource types.
Bintec XOT enabled routers, primarily used as frontend device for
remote isdn and/or x.25 links (HNAS users in Germany).
TELDAT XOT enabled routers (HNAS users in Spain).
Site License/Pricing Structure
A site license currently includes up to
three active images or instances of the active HNAS program regardless
of the logical LPAR or physical Mainframe (Host) configuration at
a single physical location. A fourth image would represent a second
site license. Some discounted site licenses provide for up
to two active images or instances per license. Each site license purchase includes maintenance and
support for the first year. A monthly or annual maintenance/use fee is
required after the first year for as long as the product is in use. HNAS
product rental or lease site licenses include maintenance/use and
support. No cost product release upgrades are available for purchased
or leased (rental) site licenses. Please contact a Comm-Pro sales
representative or Business Partner for current purchase, lease and
annual maintenance/use pricing information. Note:
The text in this section previously indicated that "A site license
currently includes up to three (3) mainframes at a single physical
location. A fourth machine would represent a second site.". The HNAS
license terminology for mainframe, machine or host has always referred
to an image or instance of the active program. Some HNAS site
licenses provide for a maximum of 2 active images per site with a 3rd
image for 'hot standby'.
Availability
All of the HNAS "XOT" and
"XTP" product components; IPAD (Integrated
PAD), XPAD (Transparent PAD), PCNE, GATE (including GATE
callout feature), and GATEFC are currently available in the Z/OS, OS/390 and MVS
distribution formats. The VM/ESA implementation for these products is not longer
provided in our standard offering. Please contact a HNAS representative
should you require VM support.
The Product Features List by Release link provides a basic list of the key
features and enhancements that were added to the respective HNAS releases.
The Product's General Availability Date is also included for each of the
denoted releases.
We suggests that potential International customers go through
one of our business partners whenever possible to take advantage
of the added value of; local language, time zones, support, etc.
Comm-Pro can support International HNAS
customers directly from their headquarters in Santa Clarita,
California (U.S.A.) should our business partner support not be available in your region.
Please refer to the International
Marketing Support - Comm-Pro Business Partners link for contact information.
For additional Comm-Pro contact
information please click here.
LINK TO SITES WITH RELATED TOPICS
Cisco Systems - Cisco
Systems Home Page
• XOT
- X.25 over TCP/IP
Product Information Link for XOT. See Request For Comments (RFC)
1613.
IBM
IBM - Networking
Products
ACF/NCP, ACF/SSP, ACF/VTAM,
EP and NPSI Documentation Links
• IBM
Communication Controller Migration Guide Abstract and Guide
(PDF 3 MB)
Refer to Chapter 6 - X.25 NCP Packet Switching Interface (NPSI)
If the Guide hyperlink fails for the PDF document, go directly to IBM
Redbooks main page and search on IBM Form Number SG24-6298-00 to locate
the document.
• IBM - Routers
Product Information Link for 2210, 2212 and 2216 Routers.
Comm-Pro is a member of the "IBM PartnerWorld for Developers" program.
HNAS
Product Documentation Information -
HNAS
Maintenance Page
Emergency Support
Information link -
Comm-Pro Contact/Information
List
of Abbreviations and Terms
Last Update - March 20, 2017