SNASw XID protocol error during activation

Question

Hello forum,
we have a cisco 7204 snasw enabled connected to 2 OSA. The configuration is as:
source-bridge ring-group 2100
dlsw local-peer peer-id 10.201.254.210 promiscuous
dlsw prom-peer-defaults tcp-queue-max 150
interface Loopback0
ip address 10.201.254.210 255.255.255.255
interface FastEthernet0/0
ip address 10.211.7.2 255.255.255.0
duplex full
speed 100
interface FastEthernet0/1
ip address 10.211.60.2 255.255.255.0
duplex auto
speed auto
snasw dlctrace format analyzer
snasw cpname EFGEURO.SNASW1
snasw port PSNASW1 FastEthernet0/1
snasw port DLSW vdlc 2100 mac 4200.0000.0001 conntype len
snasw link LSNASW1 port PSNASW1 rmac 4600.0000.00a1
snasw link L1SNASW1 port PSNASW1 rmac 4600.0000.00a3
So we have defined two snasw links, LSNASW1 and L1SNASW1 and we use also vdlc port 2100. The dlsw peer interface is the loopback. On the other side of the dlsw cloud, there is a cisco router and an SNA server (microsoft 2003).
Although the dlsw is ok, we have problems with the actual session setup:
7200_SNASW_DLSW#sh dl pe
Peers: state pkts_rx pkts_tx type drops ckts TCP uptime
TCP 10.215.41.1 CONNECT 681 56 prom 0 1 0 00:11:08
Total number of connected peers: 1
Total number of connections: 1
7200_SNASW_DLSW#sh dl ci
Index local addr(lsap) remote addr(dsap) state uptime
3925868595 4200.0000.0001(04) 0088.500c.eb1d(04) CKT_ESTABLISHED -
(notice the 42000000001 which is the vdlc mac).
But in the attached file you can see the dlctrace output error:
we get the SNASW_CS_LOG_6 message, XID protocol during activation. Is it possible to analyse the trace output?
Regards, Apostolos.

Answer 1

Hi Apostolos,
Cisco SNASw is only assisting with activating PUs and LUs by providing DLUR services. It does not replace VTAM, however it will pass all of the control flows to SNA Server as if it is coming directly from VTAM. Here is the PU/LU activation sequence:
SNA Server indicates it wants PU services on the XID it sends to SNASw.
If SNASw does not already have a DLUR-DLUS session (CPSVRMGR mode) with VTAM, it will BIND one. Then it will send a REQACTPU to VTAM, encapsulated in this LU 6.2 session. VTAM should +rsp to REQACTPU.
Next VTAM will send ACTPU down to SNASw, again encapsulated in the DLUR-DLUS session. SNASw de-encapsulates it and forwards it to SNA Server. SNA Server should return +rsp(ACTPU), and SNASw will forward this back to VTAM.
ACTLU processing is handled in a similar way.
If VTAM did not have the switch major node with the PU defined and active, VTAM would have rejected the REQACTPU and ACTPU would not have flowed. SNASw would retry REQACTPU in case the swmajnode comes active.
This is completely described in the DLUR architecture reference. You can find APPN/DLUR architecture documents at http://www.networking.ibm.com/app/aiwdoc.htm . DLUR is the 3rd document down. SSCP-PU and SSCP-LU activation is in chapter 6, and LU-LU activation is chapter 8.
Let me know if you need more detail on this, or if I've misunderstood your question.
There was no sense code in the DLC trace. It would have been in frame 397 sent by SNA Server, in the CV22 at the end of the XID. The sense code field is optional and SNA Server chose not to included it. The CV22 does include an error byte offset of x'001D'. This points to the CP name in the CV 0E in the XID previously sent by SNASw, indicating as you found that the CP name sent by SNASw was not the CP name that SNA Server configured in the link.
Regards,
Bob