Welcome to Comm-Pro Associates, Inc.

Provider of X.25 solutions and support of various NPSI LLC types in IBM Mainframe environments.  X.25 Host Network Access Support (HNAS) provides support for Cisco XOT and IBM XTP routers via the host resident TCP/IP stack (NPSI and 37xx communication controller replacement product running in the host) while X.25 37XX Network Access Support (NAS) provides enhanced support under NCP and/or EP in the IBM 37XX communication controller environment (Comm-Pro has over 30 years of experience supporting IBM 37XX Communication Controllers) .

X.25 Host NAS - Network Access Support (HNAS)
X.25 via Cisco XOT and IBM XTP Routers into Host TCP/IP Stack (NPSI Emulation)
NPSI Mainframe Connectivity Without 3745 NCP/NPSI Requirement)  -  HNAS Overview Presentation File
X.25 connectivity via Cisco and IBM routers into Z/OS, OS/390 and MVS/ESA applications via the host resident TCP/IP stack.  Installation's that no longer have a requirement for 270x emulator program applications or native SNA support should consider Comm-Pro's X.25 Host Network Access Support (HNAS)  product as a replacement for their IBM 3745's (including 3705, 3725 and 3720 communication controllers) running NCP with NPSI or NCP with our X25 37XX NAS products.   The  HNAS product can be used in conjunction with all Cisco XOT enabled routers (26nn, 36nn, 45nn, 7nnn, etc.) and the following IBM XTP routers ( 2210, 2212, 2216, 3746-900 and Net Utility).  The HNAS product can also be used for host-to-host communication (HNAS-XOT at each end) for NPSI like application-to-application without X25 facilities or XOT/XTP routers.      

HNAS is a collection of software that supports specific X.25 components in the mainframe environment without the requirement for 3745 FEPs running NCP and NPSI .  HNAS was initially developed for IBM routers but now includes support of Cisco XOT enabled routers.

X.25 virtual circuits are established between Cisco or IBM routers and X.25 networks.  The connections are passed to HNAS over a TCP/IP backbone using Cisco routers with the open protocol called XOT (X.25 over TCP/IP) or IBM's proprietary protocol called XTP (X.25 via TCP/IP).

HNAS provides, for non-SNA devices, complete emulation of NPSI functions such as GATE, GATE Fast Connect, Integrated PAD, Transparent PAD and PCNE.

HNAS now 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.

Host NAS (HNAS) EOL - Effective: December 31, 2018

Please refer to the enclosed HNAS EOL Notice (see this link). Additional information is available via HNAS Maintenance or Documentation Page link Product Notices (Important information) section Host NAS (HNAS) Release Activity - Host NAS End-Of-Life Effective December 31, 2018 for additional information.  Last updates May 28, 2018.

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.

X.25 37XX NAS - Network Access Support (NAS)
X.25 via IBM 37XX Communication Controller Support
(Over 30 years of experience supporting IBM 37XX Communication Controllers)  

 NAS37xx EOL Notice - Effective: December 31, 2015

: Comm-Pro has retired the 37XX Network Access Support Software packages. While we provided many products & features for the IBM 3705, 3720, 3725 & 3745 and Amdahl Communication Controller / Front End Processors these devices are no longer in use.       

Please select one of the above product links for specific product descriptions, domestic and international sales, support and company information.

 HNAS Product Documentation Information  HNAS Maintenance Page
Comm-Pro Contact/Information

 Emergency Support Information link  -  Notices

List of Abbreviations and Terms


   Last Update - March 13, 2018