COMM-PRO

37XX NAS
ENHANCEMENTS ON THE HORIZON

SHIP26


SHIP26, Mod 0 and some components in Mod 1 (Phase 1) are currently in production mode testing at 2 sites. The SHIP26 version of our Network Access Support (NAS) provides support for T1 speed X.25 and PPP links. X.25 support is a standard feature of our NAS product. PPP support is provided as part of the NAS TCP/IP extension package (NAS/IP). A full TCP/IP stack has been incorporated into NAS/IP allowing TELNET and TN3270 connectivity across the PPP links. PPP sessions are currently routed to Emulator Program host applications only. SHIP26, Mod 1 (see below) will extend this support to local NCP and remote host applications as well.


SHIP26 (Mod 0) New Features

In addition to the support described above, a number of new features have been incorporated into our SHIP26, Mod 0 release.

  1. The NAS dispatcher has been redesigned so that fewer CPU cycles are required to perform the same amount of work. This permits a greater number of devices to be supported within the same FEP.
  2. The NAS buffer manager has been completely reworked to eliminate wasted CPU cycles thus providing for greater data throughput. NAS access lines now take advantage of the receive buffer chaining capabilities of the 37XX scanners. Note that NAS has always used transmit buffer chaining. Receive buffers are pre-threaded to the maximum frame size so that FEP interrupts are not required when a frame exceeds the size of a buffer. The scanner automatically chains to the next buffer in the pre-threaded list without CPU intervention. The CPU is interrupted only when an entire frame has been written into FEP memory via DMA or cycle-steal transfers.
  3. Virtual Route requeue logic has been added that will prevent PIU's from getting "lost" when a virtual route becomes blocked. In prior releases, a window existed which allowed PIUs (e.g., SESSEND) to be discarded when a virtual route became blocked. This could (did) result in resources appearing active to VTAM but inactive to NAS. The resource became unavailable for reuse until the FEP was reloaded. Although this problem existed in releases prior to SHIP26, it manifests itself only rarely because the window of opportunity for failure is very small.
  4. The console subsystem has been modified to provide greater diagnostic capabilities and enhanced displays. The console is an invaluable tool for our customer support.
  5. New Sysgen parameters have been added that Parameterize options that we used to make available as custom modifications. Most custom Mods are now standard.

SHIP26, Mod 1

SHIP26, Mod 1 provides Ethernet and PPP support for IP traffic as well as RFC1490 encapsulation of IP traffic across X.25 access lines. In addition, TELNET and TN3270 connections will be able to access both EP and NCP applications. In its Phase 1 release, SHIP26, Mod 1 will allow IP traffic to be routed to a local default route (POOL). Subsequently, a Phase 2 upgrade will be available that will provide complete IP routing within NAS. This means, for example, that IP traffic entering NAS via an Ethernet link can be routed to a local host or a remote host attached via another Ethernet link, PPP link or X.25 link. Routing is link independent.

Since the TCP/IP stack is part of NAS/IP, there is no need to purchase the IBM mainframe TCP/IP program product. NAS will protocol convert TELNET and TN3270 communications traffic so that they appear as "native" devices to host applications. For locally attached hosts, TELNET connections are protocol converted to ASCII TTY "like" devices on the EP path or LU Type 1 (3767) devices on the NCP path. Similarly, TN3270 connections are protocol converted to EBCDIC BSC 3270 "like" devices on the EP path or LU Type 2 3270 devices on the NCP path.

RFC1490 Encapsulation
In addition to the IP support that is inherent to PPP and Ethernet connections, Phase 1 of SHIP26, Mod 1 allows for the encapsulation of IP traffic across X.25 access lines using the Subnetwork Access Protocol (SNAP) subset of the RFC1490 Network Level Protocol ID (NLPID). IP data encapsulated in this way can be delivered across switched (SVC) or permanent (PVC) X.25 virtual circuits.

Ethernet DIX/LLC Support
The Ethernet support that is provided in Phase 1 of SHIP26, Mod 1 allows use of the two most commonly used frame formats - Ethernet V2, developed jointly by DEC, Intel and Xerox (DIX), and IEEE 802.2 Logical Link Control (LLC). LLC frames employ the Subnetwork Access Protocol (SNAP). Ethernet stations can communicate using Type 1 Connectionless LLC service or Type 2 Connection Oriented LLC service. The latter provides end-to-end sequence checking to ensure error free delivery of all datagrams. Note that IBM's Ethernet support provides Type 1 LLC service only.

Ethernet ARP Support
The Ethernet support that is present in Phase 1 of SHIP26, Mod 1 provides for dynamic LAN station identification using the Address Resolution Protocol. This means that devices can be added and removed from the LAN without having to re-Sysgen. The presence or absence of a device is determined dynamically using ARP.

Internet RIP Support
The IP routing support that will be provided in Phase 2 of SHIP26, Mod 1 will allow NAS to assume the role of an Internet router. NAS uses the Routing Information Protocol to dynamically ascertain the "best" route to a target IP address. Routing tables are maintained completely within NAS. The IBM mainframe NCPROUTE function and its host NCST connection are NOT required.

SHIP26, Mod 1 Availability

Phase 1 of SHIP26, Mod 1 will be going into pre production testing in the first quarter of 1999. Phase 2 testing will commence shortly thereafter. Pricing for SHIP26 has not been officially set; however, we expect a modest increase for the NAS/IP product only. Our currently thinking is that a $200 per month surcharge will be added for TCP/IP support above and beyond the $500 per month cost of NAS. The TCP/IP support will allow the interconnection of Ethernet, PPP and X.25 traffic.

Refer to the SHIP26 Status link for component availability.

(Please note that the availability dates are approximate and will be prioritized according to our user's needs. Please call or E-mail us regarding your individual requirements.)

OTHER

The following products are currently under review or development:.

Last Update - June 3, 1999