[j-nsp] 4CHDS3 and M40, T1 interfaces won't come up

[James Sneeringer]

hardware: M40, P-4CHDS3
software: JunOS 4.4R3.4

I've scoured the list archives, but found nothing quite like the problem 
we've been experiencing.  We're mostly a Cisco shop, and this is the first 
Juniper we've installed.  The JunOS version is what the unit came with, 
and we don't (yet) have a support contract set up, so I can't go download 
a newer version.  I know 4.4 is quite old.

Upon configuring a T1 channel that has a live circuit on it, the M40 
indicates the interface is up, but it is unable to bring PPP up.  The 
interface counters only show outbound packets, nothing inbound.

CPE on the far end shows the same thing, no alarms, circuit up, but only 
outbound traffic.  I've tried several different CPE on the far end (Ascend 
Pipeline and Cisco gear), with the same results.  If I move the DS3 
circuit off the M40 to a Cisco 7206VXR with PA-MC-2T3+, PPP on the channel 
comes right up.  Thus, I'm pretty sure the CPE and DS3 circuit are not the 
problem.

The really strange thing is, if I enable remote loopback on the channel on 
the M40 (set t1-options loopback remote), the CPE on the far end does 
receive its own packets back.  However, the M40 still does not register 
any inbound packets.  If I enable a loopback on the CPE, the M40 does not 
see its own packets returning (or just doesn't register them).

My config on the M40 is as follows:

    interfaces {
        t3-4/3/0 {
            description "In-house CT3 connected to mux for copper T1s";
            /* The M40 provides clock because it's more reliable than the mux's. */
            clocking internal;
            t3-options {
                no-long-buildout;
                cbit-parity;
            }           
        }               
        t1-4/3/0:26 {   
            description "test circuit";
            /* The network provides DS1 clocking. */
            clocking external;
            encapsulation ppp;
            t1-options {
                timeslots 1-24;
                byte-encoding nx64;
                line-encoding b8zs;
                framing esf;
            }           
            unit 0 {    
                family inet {
                    no-redirects;
                    address 192.168.40.1/30;
                }       
            }           
        }               
    }

Output from "show interfaces t1-4/3/0:26 detail":

    Physical interface: t1-4/3/0:26, Enabled, Physical link is Up
      Interface index: 43, SNMP ifIndex: 284, Generation: 1794
      Description: test circuit
      Link-level type: PPP, MTU: 1504, Clocking: External, Speed: T1,
      Loopback: None, CRC: 16, Framing: ESF
      Device flags   : Present Running
      Interface flags: Point-To-Point SNMP-Traps
      Link flags     : Keepalives
      Keepalive settings: Interval 10 seconds, Up-count 1, Down-count 3
      Keepalive statistics:
        Input : 0 (never)
        Output: 0 (never)
      LCP state: Conf-req-sent
      NCP state: inet: Down, iso: Not-configured, mpls: Not-configured
      Statistics last cleared: Never
      Traffic statistics:
       Input  bytes  :                    0                    0 bps
       Output bytes  :              1127536                   56 bps
       Input  packets:                    0                    0 pps
       Output packets:                70471                    0 pps
      DS1   alarms   : None
      DS3   alarms   : None
      DS1   defects  : None
      DS3   defects  : None
      DS3 BERT configuration:
        BERT time period: 0 seconds, Elapsed: 0 seconds
        Algorithm: Unknown (0), Induced Error rate: 10e-0
      DS1 BERT configuration:
        BERT time period: 10 seconds, Elapsed: 0 seconds
        Induced Error rate: 10e-0, Algorithm: Unknown (0)

      Logical interface t1-4/3/0:26.0 (Index 9) (SNMP ifIndex 405) (Generation 87)
        Flags: Hardware-Down Point-To-Point SNMP-Traps Encapsulation: PPP
        Protocol inet, MTU: 1500, Flags: No-Redirects, Protocol-Down,
        Generation: 92 Route table: 0
          Addresses, Flags: Dest-route-down Is-Preferred Is-Primary
            Destination: 192.168.40.0/30, Local: 192.168.40.1,
            Broadcast: Unspecified, Generation: 188

I can't do the same for t3-4/3/0, it returns a "device not found" error.

Ideas?

-James