Tx , Rx is not balance

bamboo_007 · ‎03-12-2007

Dear All !!

My router 7206 connect to carrier router 7206, BW: 8 M , connect via satellite (P2P).

I used "only for VoIP"

Interface show, I always get Rx = 50% Tx (Ex : txload 110/255, rxload 50/255). and at the sametime

*) On my router:

30 second output rate 3475000 bits/sec, 6787 packets/sec

*) On carrier router

30 second input rate 2761000 bits/sec, 7533 packets/sec.

That is mean : on my router , I "always" send more traffic than carrier router received. I have two question, Please help me to solve it:

1- Why i only used VoIP, But Tx and Rx always much diffirent (Tx >=2 x Rx)

2- Why output rate on my router "always" more than input rate on carrier router?

(input error , out put error is very low)

I am really thanks for support.

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

show int both router

My router R7206#clear counters

Clear "show interface" counters on all interfaces [confirm]

My router R7206#clear counters sh int s4/0

Serial4/0 is up, line protocol is up

Hardware is M4T

Description: ****Link to US ****

Internet address is 192.168.2.1/24

MTU 1500 bytes, BW 8192 Kbit, DLY 20000 usec,

reliability 255/255, txload 204/255, rxload 84/255

Encapsulation HDLC, crc 16, loopback not set

Keepalive set (10 sec)

Restart-Delay is 0 secs

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 00:00:03

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: weighted fair ---> QoS is not okie

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/49/256 (active/max active/max total)

Reserved Conversations 1/1 (allocated/max allocated)

Available Bandwidth 1044 kilobits/sec

30 second input rate 2720000 bits/sec, 11183 packets/sec

30 second output rate 6555000 bits/sec, 12824 packets/sec

39074 packets input, 1181622 bytes, 0 no buffer

Received 1 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 13 ignored, 0 abort

45351 packets output, 2903907 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

(QoS is the same config for both router)

Carrier router R7206#clear counters

Clear "show interface" counters on all interfaces [confirm]

Carrier router R7206#clear counters sh int s2/1

Serial2/1 is up, line protocol is up

Hardware is M4T

Description: ***Link to China***

Internet address is 192.168.2.2/24

MTU 1500 bytes, BW 8192 Kbit, DLY 20000 usec,

reliability 255/255, txload 85/255, rxload 129/255

Encapsulation HDLC, crc 16, loopback not set

Keepalive set (10 sec)

Restart-Delay is 0 secs

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 00:00:04

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: Class-based queueing ------> QoS is Okie

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/11/256 (active/max active/max total)

Reserved Conversations 1/1 (allocated/max allocated)

Available Bandwidth 1044 kilobits/sec

30 second input rate 4167000 bits/sec, 12405 packets/sec

30 second output rate 2743000 bits/sec, 11445 packets/sec

55221 packets input, 2319112 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 66 ignored, 0 abort

48849 packets output, 1462901 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

paolo bevilacqua · ‎03-12-2007

Well, it seems to me that, assuming this is all voice traffic, the voice gateways must be using VAD, that can explain the difference in counters.

Then, one gateway appears to be using a different sample size that the other:

china router:

output 2903907 bytes, 45351 pkts = 64 B/pkt

input 1181622 bytes, 39074 pkts = 30 B/pkt

US router:

output 1462901 bytes, 48849 pkts = 30 B/ pkts

input 2319112 bytes, 55221 = 41 B/ pkts ???

So the most evident incongruence is in the packet size.

I would check voice gateway settings, perhaps enlarge the sample size a little bit.

Comparing counter then must be done over a larger time period.

if these are powerful routers like NPE-400 or better, you can consider using RTP header compression, depending of the actual CPU load.

I would not worry much about QoS, as if this is all voice traffic, there is nothing that can be prioritized (exception signaling, but is not much anyway)

bamboo_007 · ‎03-16-2007

Dear p.bevilacqua!

I am sorry , if my question is simple.

I really don't understand why packet size output from China 64b/pcks , BUT US received only 41b/pcks ? two serial connect point to point. Please exlain or give me some reasons of this case ?

Thanks for suport