Usg2160bsr through Serial port to interconnect, but the protocol cannot be up

A user uses usg2160bsr to interconnect with vender through the serial port, physical state is up, but the protocol is always down, the interconnection unsuccessful. The usg2130bsr version is v100r003, but use usg2205bsr same configuration can interconnect with vender successfully.

None

1. Check the interface state is as follows:
<USG2160BSR> Dis int s2/0/0
Serial2/0/0 current state: UP
Line protocol current state: DOWN
Description: Huawei Symantec, Secospace Series, Serial2/0/0 Interface
The Maximum Transmit Unit is 1500 bytes, Hold timer is 10 (sec)
Internet Address is X.X.1.242/30
Link layer protocol is PPP
LCP acksent
Output queue: (Urgent queue: Size / Length / Discards) 0/50/0
Output queue: (Protocol queue: Size / Length / Discards) 0/1000/0
Output queue: (FIFO queuing: Size / Length / Discards) 0/256/0
Physical layer is synchronous,
Interface is DTE, Clock is DTECLK1, Cable type is V35
    Last 300 seconds input rate 1.98 bytes / sec, 0.15 packets / sec
    Last 300 seconds output rate 3.47 bytes / sec, 0.22 packets / sec
    Input: 1341 packets, 18712 bytes
           3 errors:
           3 non octet_aligned, 0 abort sequence
           0 giants, 0 CRC, 0 overruns, 0 carrier lost
    Output: 2266 packets, 35466 bytes
           0 errors:
           0 underruns, 0 CTS lost errors
    DCD = UP DTR = UP DSR = UP RTS = UP CTS = UP
   The LCP state is acksent, initially think it appears abnormal in the LCP stage.
2. From the device debug ppp to view the debug information:
* 0.1500683 USG2160BSR PPP/7/debug2:
  PPP Packet:
      Serial2/0/0 Output LCP (c021) Pkt, Len 18
      State acksent, code ConfReq (01), id da, len 14
      MRU (1), len 4, val 05dc
      MagicNumber (5), len 6, val 00173950
* 0.1501833 USG2160BSR PPP/7/debug2:
  PPP Packet:
      Serial2/0/0 Input LCP (c021) Pkt, Len 14
      State acksent, code ConfReq (01), id a, len 10
      MagicNumber (5), len 6, val 0883dbf7
* 0.1502083 USG2160BSR PPP/7/debug2:
  PPP Event:
      Serial2/0/0 LCP RCR + (Receive Config Good Request) Event
      state acksent
* 0.1502250 USG2160BSR PPP/7/debug2:
  PPP Packet:
      Serial2/0/0 Output LCP (c021) Pkt, Len 14
      State acksent, code ConfAck (02), id a, len 10
      MagicNumber (5), len 6, val 0883dbf7
* 0.1502883 USG2160BSR PPP/7/debug2:
  PPP Event:
      Serial2/0/0 LCP TO + (Timeout with counter> 0) Event
      state acksent, Retransmit = 4
Found that both ends are able to receive the other ConfReq messages, but usg2160bsr issued ConfAck message, but can not receive peer end response messages, made it always in acksent state. Negotiation timeout “LCP TO + (Timeout with counter> 0) . In the LCP it generally cause by clock signal, the both ends devices lose synchronization or a large packets are discarded, DTE side synchronous serial transmit clock signal can flip to eliminate the impact of the delay. 
3. Solution:
The Serial2/0/0 interface configure execute command “invert transmit-clock”, Serial2/0/0 interface protocol up, communication normal, and problems have been solved.

1. Version does not support.
2. Version features issue.

This problem should be the usg2160bsr v100r003 device characteristics of reason, this command only can take effect to some DCE devices provide the clock signal. And only configure at the DTE side. For normal applications, should not be configured clock flip.