Symptom
Well running TCP/IP connections break down when sending or receiving larger data packets (about 2000 bytes up to 5000 bytes).
-> "connection to partner broken" at the sapgui
-> "Connection timed out" in the R/3-System
-> "connection to partner broken" at the sapgui
-> "Connection timed out" in the R/3-System
Other Terms
MSS (maximum segment size) IP-fagmentation
Reason and Prerequisites
If applications send data-packets larger than the MTU-size (maximun
transmission unit) of the underlying network these data-packets must be
fragmented into serveral packets less than or equal MTU-size.
Please note that these kind of problems belong to your specific TCP/IP configruation and are normally no SAP-Problems.
In FDDI networks the normal MTU-Size is 4352 bytes. That can be verified using the command: netstat -i
The normal ethernet packet size is about 1500 Bytes. So Routers between FDDI and Ethernet must fragment and defragment packets larger than 1500 Bytes. WAN-Lines may have other (smaller) MTU-Sizes.
To check wether or not you have that problem you may use the niping program. (SAP Program)
You may vary the blocksize from 1000 Bytes up to 5000 Bytes. Please envolve your networking guys to solve that ploblem.
It may be necessary to use network-analysers to check which component isn't able to do the fragmentation/defragmentation (IP-layer).
May be the PC's TCP/IP-Stack isn't able to reassemble fragmented TCP/IP packets.
Please note that these kind of problems belong to your specific TCP/IP configruation and are normally no SAP-Problems.
In FDDI networks the normal MTU-Size is 4352 bytes. That can be verified using the command: netstat -i
The normal ethernet packet size is about 1500 Bytes. So Routers between FDDI and Ethernet must fragment and defragment packets larger than 1500 Bytes. WAN-Lines may have other (smaller) MTU-Sizes.
To check wether or not you have that problem you may use the niping program. (SAP Program)
- 1. Start the niping server on the R/3-computer. (login as R/3-adm user)
command: niping -s -I0 &
- 2. Start the niping client on the frontend (PC)
command: niping -c -B 5000 -H <hostname>
You may vary the blocksize from 1000 Bytes up to 5000 Bytes. Please envolve your networking guys to solve that ploblem.
It may be necessary to use network-analysers to check which component isn't able to do the fragmentation/defragmentation (IP-layer).
May be the PC's TCP/IP-Stack isn't able to reassemble fragmented TCP/IP packets.
Solution
The solution of this problem must be found and done in the networking
environment. One possibility is to set MTU-size to the smallest MTU of
any data link that packets traverse between the PC and the R/3-Host.
However the data sent by the SAP-applications depend on the amount of application-data and may vary in a wide range.
However the data sent by the SAP-applications depend on the amount of application-data and may vary in a wide range.
Header Data
| Released On | 18.12.1996 23:00:00 |
| Release Status | Released for Customer |
| Component | BC-NET Network Infrastructure |
| Priority | Recommendations / Additional Info |
| Category | Customizing |
No comments:
Post a Comment