Conference irocz::common_brouters

765.0. "RouteAbout 90EW/IP V1.1.005 DCD signal not seen" by IAMOSI::LEUNG () Thu Feb 20 1997 01:32

RtAbt Acces EW/IP, Brouter: 1 Enet 2T1,HW=1,RO=1,#6053,SW=V01.1.005
V.35 Cable to NEC ISDN TA

Customer manually dials on the TA to the remote site. The RouteAbout cannot see the
DSR, DCD signals from the TA and therefore the interface stays in DOWN state. 
If customer replaces the RouteAbout with a DECBrouter using the same V.35 cable and
ISDN TA, the brouter works fine.

+int 1
                                Self-Test  Self-Test  Maintenance
Nt Nt' Interface      CSR  Vec     Passed     Failed       Failed
1  1   PPP/0      1001620   5D          0        165            0
  Point to Point MAC/data-link on SCC Serial Line interface

  Adapter cable:               V.35 DTE  RISC Microcode Revision:            0

   V.24 circuit: 105 106 107 108 109 125 141
   Nicknames:    RTS CTS DSR DTR DCD RI  LL
   PUB 41450:    CA  CB  CC  CD  CF  CE
   State:        ON  ON  OFF ON  OFF OFF OFF  <<<<<<<<<<<<<<<<<

  Line speed:              unknown
  Last port reset:         1 minute, 46 seconds ago

  Input frame errors:
   CRC error                          0   alignment (byte length)            0
   missed frame                       0   too long (>  2182 bytes)           0
   aborted frame                      0   DMA/FIFO overrun                   0
   L & F bits not set                 0
  Output frame counters:


If customer puts the local ISDN TA into local LOOPBACK, the signals come up fine.
+inter 1
                                Self-Test  Self-Test  Maintenance
Nt Nt' Interface      CSR  Vec     Passed     Failed       Failed
1  1   PPP/0      1001620   5D          0          9            0

  Point to Point MAC/data-link on SCC Serial Line interface

  Adapter cable:               V.35 DTE  RISC Microcode Revision:            0

   V.24 circuit: 105 106 107 108 109 125 141
   Nicknames:    RTS CTS DSR DTR DCD RI  LL
   PUB 41450:    CA  CB  CC  CD  CF  CE
   State:        ON  ON  ON  ON  ON  OFF OFF  <<<<<<<<<<<<<<<<<<<

  Line speed:              unknown
  Last port reset:         2 minutes, 44 seconds ago

  Input frame errors:
   CRC error                          0   alignment (byte length)            3
   missed frame                       1   too long (>  2182 bytes)           0
   aborted frame                      2   DMA/FIFO overrun                   0
   L & F bits not set                 0
  Output frame counters:
   DMA/FIFO underrun errors           0   Output aborts sent                 0


If customer put the ISDN TA back into NORMAL mode (i.e not in loopback), the following
message can be seen in ELS :

 PPP.035: mk mru 2048
 PPP.038: mk mag 0x526118E0
 PPP.016: LCP/Req Sent snd Configure Request, id 243 len 14, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = OFF, DCD = OFF, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = OFF, DCD = ON, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = ON, DCD = ON, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = ON, DCD = OFF, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = OFF, DCD = OFF, nt 1 int PPP/0
 PPP.014: LCP/Req Sent fsm_timeout nt 1 int PPP/0
 PPP.018: LCP request retr exc nt 1 int PPP/0
 PPP.014: LCP/Req Sent fsm_reset nt 1 int PPP/0
 PPP.019: LCP/Listen lcp_reset nt 1 int PPP/0
  SL.023: int dwn bcs of mdm sts, CTS = ON, DSR = OFF, DCD = OFF, nt 1 int PPP/0
 ETH.046: IPX pkt in ETHERNET_802.2  encap ign, using ETHERNET_802.3  encaps, nt
 0 int Eth/0
  SL.007: st slftst nt 2 int PPP/1
  SL.021: slf tst fl bcs of mdm sts, CTS = OFF, DSR = OFF, DCD = OFF, nt 2 int P
PP/1
  SL.022: Modem status change CTS = ON, DSR = OFF, DCD = ON, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = ON, DCD = ON, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = ON, DCD = OFF, nt 1 int PPP/0
  SL.023: int dwn bcs of mdm sts, CTS = ON, DSR = ON, DCD = OFF, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = OFF, DCD = OFF, nt 1 int PPP/0
  SL.007: st slftst nt 1 int PPP/0
  SL.021: slf tst fl bcs of mdm sts, CTS = ON, DSR = OFF, DCD = OFF, nt 1 int PP
P/0

The signals (DSR and DCD) go ON for a short while but then goes into OFF state.

Dennis

    The TA is up and connected to the remote site during these tests?
    
    We depend on DSR and DCD being asserted on serial interfaces.  If not,
    the circuit is marked down as you discovered.  What make of TA is this? 
    Why is it cycling DCD up and down that way?
    
    I'm not sure why the BRUT works; perhaps they ignore modem control?
    
    It would be helpful to get a line anaylyzer and see if there is
    something else going on (RouteAbout not asserting one of its signals,
    or somesuch).

>    The TA is up and connected to the remote site during these tests?
Yes

>    We depend on DSR and DCD being asserted on serial interfaces.  If not,
>    the circuit is marked down as you discovered.  What make of TA is this? 
>    Why is it cycling DCD up and down that way?
NEC PABX Model : NEAX 2400 SDS
NEC DA-010 Data Adaptor V.35 interface
According to the manual with that adaptor, this Data adaptor does NOT provide
DCD and the suggestions it make, is to short-circuit the DSR (Pin E) and RLSD
(Pin F) to provide DCD signal. The customer has short-circuited DSR and DCD on
the V.35 cable.


These are the events from ELS immediately after the ISDN line is brought up :
*t 2
  SL.022: Modem status change CTS = ON, DSR = OFF, DCD = ON, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = ON, DCD = ON, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = ON, DCD = OFF, nt 1 int PPP/0
  SL.022: Modem status change CTS = ON, DSR = OFF, DCD = OFF, nt 1 int PPP/0
  SL.023: int dwn bcs of mdm sts, CTS = ON, DSR = OFF, DCD = OFF, nt 1 int
PPP/0
  SL.007: st slftst nt 1 int PPP/0


Corresponding debug messsages on the Brouter when ISDN line is brought up:
MK5(0): New serial state = 0x00

MK5(0): DCD is up.
%LINK-5-CHANGED: Interface Serial0, changed state to up  <<<< Interface is UP
PPP Serial0: I LCP TERMREQ id 2 (4)                      <<<< LCP negotation
starts
PPP Serial0: O LCP TERMACK id 2 (4)
PPP Serial0: O LCP CONFREQ id C (4)
PPP Serial0: I LCP CONFREQ id 4 (9) AUTHTYPE (5) 194 35 5
PPP Serial0: I LCP CONFACK id 4 (9) AUTHTYPE (5) 194 35 5
PPP Serial0: I LCP CONFACK id C (4)

It seems that the Brouter is only monitoring the DCD signal to indicate that
the interface is up whereas the RouteAbout expects both DSR and DCD.
Can the RouteAbout handle the fact that DSR and DCD are short-circuited?

Thanks
Dennis

Oops, forgot to add that RouteAbout has been upgraded to V2.0-0 without
success. 
The traces done in .2 are when V2.0-0 is used.

    I would wire (short circuit) DTR to DSR & DCD.  The router will assert
    DTR, and will think it sees DSR & DCD; it should work then.
    
    Not sure what is going on in the current configuration.  If DSR and DCD
    are wired together, then it must be DSR that is going up and down.
    Again, the router doesn't like this.  I don't know what the BRUT is
    doing differently (perhaps ignoring modem control entirely)?
    
    Tim

RE: .4

That did the trick, The serial interface is up and working.

Thanks
Dennis