TC4.X TCP Timeout.

[Niklas Johansson]

Hi,

Does anyone know the TCP timeout on a C- or a Ex- Series system?

Jordan: I saw your post in the "old" Tandberg forum. Therefore the post here.

I would really like to the timeouts for all three if you have them. SIP, H323 and HTTP.

Rgs

Niklas

[Niklas Johansson]

Does anyone know about this?

//Niklas

[Justin Ferello]

Niklas,

There is no TCP timeout coded into any Cisco codec.  There is not even a maximum call duration, except for ISDN on the MXP line of codecs.  Are you having a problem with something?

Thanks,

Justin

[Martin Koch]

If there would be no timeouts it would be a bad thing, how should it ever clean out dropped connections, ...

If I see it right these are the generic timeouts on a TC4.1 system:

icmp_timeout:30
tcp_timeout_close:10
tcp_timeout_close_wait:60
tcp_timeout_established:432000
tcp_timeout_fin_wait:120
tcp_timeout_last_ack:30
tcp_timeout_max_retrans:300
tcp_timeout_syn_recv:60
tcp_timeout_syn_sent:120
tcp_timeout_time_wait:120
tcp_timeout_unacknowledged:300
udp_timeout:30
udp_timeout_stream:180

tcp_max_retrans:3

If everything works fine you will not experience these as you do not need to care as

the upper layers take care that it will either not expire or reestablish a new connection.

So the main question here is why Niklas asks and if which problem he experiences.

If any timeout or disconnect occurs its most likely a firewall or an other "clever" Layer3 device.

[scpage]

After all, these codecs all run a Linux kernel.  Use sysctl command to see stack parameters.

From and ex90...

[ex90-01-rtp:/extra/sbin] $ sysctl -a | grep tcp
fs.nfs.nlm_tcpport = 0
net.netfilter.nf_conntrack_tcp_timeout_syn_sent = 120
net.netfilter.nf_conntrack_tcp_timeout_syn_recv = 60
net.netfilter.nf_conntrack_tcp_timeout_established = 432000
error: permission denied on key 'net.ipv4.route.flush'
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60
net.netfilter.nf_conntrack_tcp_timeout_last_ack = 30
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close = 10
net.netfilter.nf_conntrack_tcp_timeout_max_retrans = 300
net.netfilter.nf_conntrack_tcp_timeout_unacknowledged = 300
net.netfilter.nf_conntrack_tcp_loose = 1
net.netfilter.nf_conntrack_tcp_be_liberal = 0
net.netfilter.nf_conntrack_tcp_max_retrans = 3
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_retrans_collapse = 1
net.ipv4.tcp_syn_retries = 5
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_max_orphans = 4096
net.ipv4.tcp_max_tw_buckets = 180000
net.ipv4.tcp_keepalive_time = 7200
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_intvl = 75
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_retries2 = 15
net.ipv4.tcp_fin_timeout = 60
net.ipv4.tcp_syncookies = 0
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_abort_on_overflow = 0
net.ipv4.tcp_stdurg = 0
net.ipv4.tcp_rfc1337 = 0
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_orphan_retries = 0
net.ipv4.tcp_fack = 1
net.ipv4.tcp_reordering = 3
net.ipv4.tcp_ecn = 2
net.ipv4.tcp_dsack = 1
net.ipv4.tcp_mem = 47520        63360   95040
net.ipv4.tcp_wmem = 4096        16384   2027520
net.ipv4.tcp_rmem = 4096        87380   2027520
net.ipv4.tcp_app_win = 31
net.ipv4.tcp_adv_win_scale = 2
net.ipv4.tcp_tw_reuse = 0
net.ipv4.tcp_frto = 2
net.ipv4.tcp_frto_response = 0
net.ipv4.tcp_low_latency = 0
net.ipv4.tcp_no_metrics_save = 0
net.ipv4.tcp_moderate_rcvbuf = 1
net.ipv4.tcp_tso_win_divisor = 3
net.ipv4.tcp_congestion_control = reno
net.ipv4.tcp_abc = 0
net.ipv4.tcp_mtu_probing = 0
net.ipv4.tcp_base_mss = 512
net.ipv4.tcp_workaround_signed_windows = 0
net.ipv4.tcp_slow_start_after_idle = 1
net.ipv4.tcp_available_congestion_control = reno
net.ipv4.tcp_allowed_congestion_control = reno
net.ipv4.tcp_max_ssthresh = 0

[Niklas Johansson]

Hi,

And thanks for the replies. My issue is/was that the calls dropped for no apparent reason. And I had to explore every possibility. The traffic flow went throught several firewalls and routers. So after triyng everything else I thought I would check the timeouts as well, even if I did not accually thought that the timeout would be the thing that caused my problem.

But before I could get ahold of thease timeouts TAC told me to try and switch switch of "Enable ad-hoc conference discovery" in the TMS. That did the trick.

So my issue is resolved short term anyway.

Cheers

Niklas

[Justin Ferello]

Niklas,

Thanks for the update, thats an odd setting to cause the problem you were seeing though.

For everyone else :)

As I stated, there are no 'User' configurable time outs in any of the codecs.  Second the pre-defined timeouts would only occur if the network was not functioning properly and the codec was not getting packets back in the correct amount of time.

Thanks,

Justin