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New Member

MICA and Modem speed Negotiation

hello all, I have a 3620 with a MICA mard with PRI ISDN access.

Using debugs I've notived that each call has an average time to go thru the router of 150 ms. This looks to be due to speed negotiation for the modems.

Is there a way to improve this time ? What would be the inpact of having a fixed speed ?

Many thanks, Alex

3 REPLIES
New Member

Re: MICA and Modem speed Negotiation

What version of mica firmware are you running(sh modem ver)? If you are not running 2.7.3.0 you should upgrade. If you have a modemcap applied what is it(sh run | inc modemcap)? Get a "sh modem op x/y" for a bad connection(x/y=slot/port). What kind of client modems are there, and can you get the firmware rev's they are on?

First check your "sh controller t1/e1" for errors.

Josh

New Member

Re: MICA and Modem speed Negotiation

hello Josh, thanks for your reply.

No modem cap,

version is 2.7.3.0

but what i was wrong was on the problme description: in fact now I wonder if I could decrease the following time: analogue client - FE of the 3620.

Reply from 10.69.1.35: bytes=32 time=150ms TTL=255

Reply from 10.69.1.35: bytes=32 time=191ms TTL=255

Reply from 10.69.1.35: bytes=32 time=230ms TTL=255

Reply from 10.69.1.35: bytes=32 time=161ms TTL=255

in this case the client has connected with the following, but most of them I'm not sure I can understand.

3620NAS1#sh mod op 0/25

Modem (0/25) Operational Status:

Parameter #0 Disconnect Reason Info: (0x0)

Type (=0 ):

Class (=0 ): Other

Reason (=0 ): no disconnect has yet occurred

Parameter #1 Connect Protocol: LAP-M

Parameter #2 Compression: V.42bis both

Parameter #3 EC Retransmission Count: 60

Parameter #4 Self Test Error Count: 0

Parameter #5 Call Timer: 76 secs

Parameter #6 Total Retrains: 0

Parameter #7 Sq Value: 3

Parameter #8 Connected Standard: V.90

Parameter #9 TX,RX Bit Rate: 48000, 31200

Parameter #11 TX,RX Symbol Rate: 8000, 3200

Parameter #13 TX,RX Carrier Frequency: 0, 1920

Parameter #15 TX,RX Trellis Coding: 0, 16

Parameter #16 TX,RX Preemphasis Index: 25, 1

Parameter #17 TX,RX Constellation Shaping: Off, Off

Parameter #18 TX,RX Nonlinear Encoding: Off, Off

Parameter #19 TX,RX Precoding: Off, Off

Parameter #20 TX,RX Xmit Level Reduction: 0, 0 dBm

Parameter #21 Signal Noise Ratio: 40 dB

Parameter #22 Receive Level: -17 dBm

Parameter #23 Frequency Offset: -1 Hz

Parameter #24 Phase Jitter Frequency: 0 Hz

Parameter #25 Phase Jitter Level: 0 degrees

Parameter #26 Far End Echo Level: -31 dBm

Parameter #27 Phase Roll: 0 degrees

Parameter #28 Round Trip Delay: 20 msecs

Parameter #30 Characters transmitted, received: 5577, 3885

Parameter #32 General Portware Information: 0

Parameter #33 PPP/SLIP packets transmitted, received: 66, 78

Parameter #35 PPP/SLIP packets received (BAD/ABORTED): 0

Parameter #36 EC packets transmitted, received OK: 147, 157

Parameter #38 Moving Average of EC packets (Received BAD/ABORTED): 0

Parameter #39 Robbed Bit Signalling (RBS) pattern: 0

Parameter #40 Digital Pad: None

Digital Pad Compensation : Enabled

Parameter #42 SS7/COT Status: 0

Parameter #43 V110/PIAFS frames received bad: 0

Parameter #44 V110/PIAFS frames received good: 0

Parameter #45 V110/PIAFS frames transmitted: 0

Parameter #46 V110/PIAFS sync lost: 0

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Is there a way to decrease these 150 seconds ?

many thanks, Alex

New Member

Re: MICA and Modem speed Negotiation

Looks like a pretty good connection to me. What is your processor running at(sh proc cpu)? What switching path are you using for your async connections(sh ip int asyncX)? Do your users complain of slow connections? Can you run some ttcp tests and provide figures for those:

http://www.cisco.com/warp/public/471/ttcp.html

Josh

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