vFragmentation of TCP and UDP datagrams into segments that match the MTU
size.
vStarting with V4R2, AS/400 collects all TCPdatagrams in one batch and UDP
datagrams in a second batch. Ports and IP addresses are ignored. Releases
prior to V4R2 batch together datagrams at the IOP when these conditions are
true:
– The protocol (TCP or UDP) matches
– The source and destination ports match
– The source IP address and destination IP address match
– They arrive consecutively into the IOP
The IOP then passes the datagram batch to IP.
vHandling of IP and ICMP datagrams in error (unless IP NAT,which disables this
function, is active)
vResolving physical addresses using ARP protocol
These functions are called
TCP/IP-assist functions
. Whether these functions are
done by the IOP or the System Licensed Internal Code (SLIC), depends on the IOP
type, the OS/400 release, and the TCP/IP configuration. For details about specific
functions, contact your local service representative. TCP/IP-assist functions are
available on these IOPs:
v#2617 Ethernet/IEEE 802.3 adapter/HP
v#2619 16/4 Mbps Token-RingNetwork adapter/HP
v#2618 Fiber distributed data interface adapter (FDDI)
v#2665 Shielded distributed data interface adapter (SDDI)
v#2666 High-speed communication adapter that is running frame relay only
v#2668 AS/400 wireless LAN adapter
Note: Youcan get the same function without using one of the above IOP adapters
(done instead at a higher level in the system (SLIC)). When you use the
X.25 protocol, you do not gain the advantage of the TCP/IP-assist function.
The
TCP/IP-assist functions
are also available on the following LAN IOAs and ATM
IOAs:
v#2723 PCI Ethernet IOA
v#2724 PCI Token-RingIOA
v#2838 PCI 100/10 Mbps Ethernet IOA
v#6149 16/4 Mbps Token-RingIOA
v#2811 PCI 25 Mbps UTPATM IOA
v#2812 PCI 45 Mbps Coax T3/DS3 ATMIOA
v#2813 PCI 155 Mbps MMF ATMIOA
v#2814 PCI 100 Mbps MMF ATMIOA
v#2815 PCI 155 Mbps UTP 0C3 ATMIOA
v#2816 PCI 155 Mbps MMF ATMIOA
v#2818 PCI 155 Mbps SMF 0C3 IOA
v#2819 PCI 34 Mbps Coax E3 ATMIOA
Note: If you configure your 100 Mbps ethernet line for TCPONLY,all IOP assist
functions are disabled.
426 OS/400 TCP/IPConfiguration and Reference V4R4
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|