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Serial vrs. Sync/Async

kaisfouad
Level 1
Level 1

Hi,

Cisco router supports HWIC-4T (Serial High-Speed WAN) and HWIC-4A/S (Asynchronous/Synchronous High-Speed WAN).

What are the differece?

I couldn't find a clear answer.

Thanks for clarification..

12 Replies 12

paolo bevilacqua
Hall of Fame
Hall of Fame

Instead of looking at the products (there are many), let's look at your needs.

What is that you need to do?

Hi Paolo,

I have an old server connected to old 36xx cisco router with NM-4T serial module through RS449 cable (serial to RS449 cable).

To replace, I bought 39xx router with HWIC-4T serial WIC (smart serial to RS449 cable).

Copied the same configuration to the new router interface,,, but not working, the router is not sensing any device connected on the other side of the cable-Layer 1 issue.

(Note: same new cable and new router works fine with other servers, so the new router, new cable, and HWIC are fine)

Re-connecting to old router, every thing is fine.

On the documentaion of the serial interface on the server, it mantion as "syncronous serial interface"

I thought if replacing HWIC-4t with HWIC-4A/S may solve the issue.

Please post "show run interface x/y", "show interface ser X/Y" and "show controller ser X/Y" taken on the old working router, and then on the new non-working router.

Do not use attachments, just paste output in using courier font.

Sure, I will post when I'll be back to office the day after tomorrow..

According to Cisco, HWIC-4T replaces NM-4T, any idea if they are syncronous interfaces?

Yes, both are serial synchronous interfaces.

What works with one, is supposed to work with the other.

Hi,

Below is the output of "show serial" , "show run serial", and "show controll serial" for the old working router.

Then the same for the new not working one.

The available font here is the New Courier only..
=========================================================
For the old working router

----------------------------------

ROUTER1#show run int s 1/2
Building configuration...Current configuration : 125 bytes
!
interface Serial1/2
no ip address
encapsulation x25 dce
serial restart-delay 0
clockrate 64000
end
ROUTER1#
ROUTER1#show int s 1/2
Serial1/2 is up, line protocol is up
  Hardware is M4T
  MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation X25, crc 16, loopback not set
  Restart-Delay is 0 secs
  X.25 DCE, address , state R1, modulo 8, timer 0
      Defaults: idle VC timeout 0
        cisco encapsulation
        input/output window sizes 2/2, packet sizes 128/128
      Timers: T10 60, T11 180, T12 60, T13 60
      Channels: Incoming-only none, Two-way 1-1024, Outgoing-only none
      RESTARTs 116/0 CALLs 2331674+120/78401+180/78401+0 DIAGs 0/0
  LAPB DCE, state CONNECT, modulo 8, k 7, N1 12056, N2 20
      T1 3000, T2 0, interface outage (partial T3) 0, T4 0
      VS 1, VR 7, tx NR 7, Remote VR 1, Retransmissions 0
      Queues: U/S frames 0, I frames 0, unack. 0, reTx 0
      IFRAMEs 200411611/105881496 RNRs 0/118 REJs 0/12 SABM/Es 173/58 FRMRs 0/0 DISCs 0/83
  Last input never, output 00:00:04, output hang never
  Last clearing of "show interface" counters 1y42w
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue :0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     124983716 packets input, 631091430 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     305592471 packets output, 2701735131 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     0 output buffer failures, 0 output buffers swapped out
     11 carrier transitions     DCD=up  DSR=up  DTR=up  RTS=up  CTS=upROUTER1# ROUTER1# ROUTER1#show controll s 1/2
M4T: show controller:
PAS unit 2, subunit 2, f/w version 1-45, rev ID 0x2800001, version 3
idb = 0x61CF0E38, ds = 0x61CF2938, ssb=0x61CF2C18
Clock mux=0x0, ucmd_ctrl=0x1C, port_status=0x3D
Serial config=0x8, line config=0x200
maxdgram=1608, bufpool=48Kb, 120 particles
     DCD=up  DSR=up  DTR=up  RTS=up  CTS=up
line state: up
cable type : V.11 (RS-449) DCE cable, received clockrate 64000base0 registers=0x3C800000, base1 registers=0x3C802000
mxt_ds=0x61FAAB58, rx ring entries=40, tx ring entries=128
rxring=0x3DC8100, rxr shadow=0x61CF750C, rx_head=32
txring=0x3DC8280, txr shadow=0x61CF7718, tx_head=55, tx_tail=55, tx_count=0
throttled=0, enabled=0
rx_no_eop_err=0, rx_no_stp_err=0, rx_no_eop_stp_err=0
rx_no_buf=0, rx_soft_overrun_err=0, dump_err= 0, bogus=0, mxt_flags=0x20
tx_underrun_err=0, tx_soft_underrun_err=0, tx_limited=1(2)
tx_fullring=0, tx_started=305590442

========================================================= =========================================================
For the new not working router

----------------------------------------

ROUTER2#show run inter s0/0/1
interface Serial0/0/1
no ip address
encapsulation x25 dce
clock rate 64000 ROUTER2#show inter s0/0/1
Serial0/0/1 is down, line protocol is down
  Hardware is HWIC-Serial
  Description: OMC-S
  MTU 1500 bytes, BW 2048 Kbit/sec, DLY 20000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation X25, loopback not set
  Keepalive set (10 sec)
  CRC checking enabled
  X.25 DCE, version 1984, address , state R/Inactive, modulo 8, timer 0
      Defaults: idle VC timeout 0
        cisco encapsulation
        input/output window sizes 2/2, packet sizes 128/128
      Timers: T10 60, T11 180, T12 60, T13 60
      Channels: Incoming-only none, Two-way 1-1024, Outgoing-only none
      RESTARTs 1/0 CALLs 0+0/0+0/0+0 DIAGs 0/0
  LAPB DCE, state DISCONNECT, modulo 8, k 7, N1 12056, N2 20
      T1 3000, T2 0, interface outage (partial T3) 0, T4 0
      VS 0, VR 0, tx NR 0, Remote VR 0, Retransmissions 0
      Queues: U/S frames 0, I frames 0, unack. 0, reTx 0
      IFRAMEs 1/1 RNRs 0/0 REJs 0/0 SABM/Es 1/0 FRMRs 0/0 DISCs 0/0
  Last input 00:44:49, output 00:16:32, output hang never
  Last clearing of "show interface" counters 00:44:27
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     69 packets input, 141 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     70 packets output, 145 bytes, 0 underruns
     0 output errors, 0 collisions, 33 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out
     1193 carrier transitions
     DCD=down  DSR=up  DTR=down  RTS=down  CTS=up
ROUTER2#show controllers serial0/0/1
Interface Serial0/0/1
Hardware is HWIC-Serial
No serial cable attachedclock rate 64000
idb at 0x1441608, driver data structure at 0x133EE7E4
Stats for LED(s):
Loopback bitmask 0x0
LED1 is Green
HWIC Register Base: 0xEC000000
------------------
HWIC Common Registers:
---------------------
id(0x00):  0x00000001     rev(0x01): 0x00000002     status(0x02): 0x00000000
tx crc(0x01): 0x00000000  ctrl(0x06): 0x00008081HWIC Serial Common Registers:
----------------------------
hwic_serial_rev(0x1000): 0x07292004       hwic_serial_ctrl(0x1004): 0x00008009
intr1_enable(0x1020): 0x0000002A          intr2_enable(0x1022): 0x0000000FHWIC Serial SCC Registers:
----------------------------
ch_mode_cfg: 0x08019031    ch_flag_cfg: 0x0000007E    ch_floctrl_cfg: 0x00000000
ch_int_enable: 0x000009FF  ch_cmd_stat: 0x00000050HWIC Serial DMA Registers:
-------------------------
Rx ring_start_ptr: 0x3D822040              Rx ring_mask_index: 0x01F80000
internal_desc_stat: 0x0400060C             internal_buff_addr: 0x3D8A39C8
internal_context: 0x00000013               internal_fifo_data: 0x3D856688
Tx ring_start_ptr: 0x3D824040              Tx ring_mask_index: 0x03F80000
internal_desc_stat: 0x00000000             internal_buff_addr: 0x3D380E58
internal_context: 0x00000001               internal_fifo_data: 0x01310E56HWIC Serial Interface Registers:
-------------------------------
intf_ctrl: 0x001F modem_ctrl: 0xE11D flow_ctrl: 0x7000 brg dvdr:0x007EHWIC TDM/FREQ Counter Registers:
--------------------------------
tdm_control: 0x0000 tdm_a_8k_divider: 0x0000 tdm_b_8k_divider: 0x0000
freq_count_port_sel: 0x0000 freq_count: 0x064A0 input aborts on receiving flag sequence
0 throttles, 0 enables
0 overruns
0 transmitter underruns
0 transmitter CTS losts
0 aborted short frames
0 CRC short frames count
0 rxintr, 0 txintr, 0 rxerr, 0 txerr
0 rx_bogus_pkts, rx_bogus_flag FALSE
0 tx_abort, 0 tx_reset
tx_limited = 1(2) tx_count = 0
idb at 0x1441608, driver data structure at 0x133EE7E4
Receive Ring
rxr head (0)(0x3D822040), rxr tail (0)(0x3D822040)
buffer size 1524

=========================================================

paolo bevilacqua
Hall of Fame
Hall of Fame

From new router:

ROUTER2#show show controllers serial0/0/1
Interface Serial0/0/1
Hardware is HWIC-Serial
No serial cable attachedclock rate 64000

Is the cable cisco original ?

Can you try another port in the same module ?

Which exact IOS are you using on new router ?

Is the cable cisco original ?

I am not quite sure, but I tried this cable and other couple of cables, all are working fine with other servers

Can you try another port in the same module ?

I did that, same result, it is not sensing any cable is attached on the other end

Which exact IOS are you using on new router ?

IOS is (C3900-UNIVERSALK9-M), Version 15.0(1)M3, RELEASE SOFTWARE (fc2)

Router is fine, module and ports are fine, cables are fine, IOS is fine... all are working with other servers

Also, the server and it's serial interface are fine because they are working fine with the other router

The only difference is NM-4T and HWIC-4T.. that's why I suspecting other parameters.. and whether those modules are "really" identical

 

Router is fine, module and ports are fine, cables are fine, IOS is fine... all are working with other servers

No they are not fine, because the router does not detect the cable attached.

You should contact the TAC about this and ask them to reproduce the problem. They do not need to do the complete setup, just connect a cable same as your in a HWIC-4Y, and verify if it gets detected. Before you do that, it would be a good idea to verify that your cable is Cisco original.

As they are functioning normally with other servers, I assumed that they are fine..

And even if Cisco will reproduce the setup, may be the problem will not appear.. same as for me, some servers are working without any issue, all are Sun servers.

All cisco has to do, is reproduce the fact that DCE cable is not detected.

Nothing else is relevant.

paolo bevilacqua
Hall of Fame
Hall of Fame

The point is that cable do not fuction with HWIC-4T, because the router does not detect it.

It is not said that the cable is faulty, only Cisco TAC and DE can give a final answer.

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