WHAT ARE THE ARCHITECTED SNA SESSION LIMITS
ITEM: RTA000038147
QUESTION:
My customer has some questions regarding SNA Services/6000 and
SNA Server/6000. Could you please answer the following for both
products?
1. What is the maximum number of PUs (attachments?) that can be
active at one time - (a) what is the architected limit, and (b) how
would one determine a practical limit?
2. In (1), is the answer dependant on the number of network adapters
installed, and if so, what is the limit per token-ring adapter?
3. What is the maximum number of LU 6.2 connections - total or per PU -
that can be active at one time - again, (a) what is the architected
limit, and (b) how would one determine a practical limit?
4. Is there an architected maximum number of token ring adapters that
are supported, or is it based only on the maximum number supported by
the RISC System/6000 and AIX?
5. Are there any other limits that we should be aware of, especially
any resource limits per token-ring adapter?
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A: I will respond to your questions in the order you asked them.
1. We need to distinguish between PUs and attachments. In SNA
Services/6000, each Token Ring or Ethernet adapter, or port on a
multi-protocol adapter, is considered a PU. That is to say,
only one PU can be associated with a communications adapter (or
port). This is a limitation of SNA Services/6000, not of the
SNA architecture.
With SNA Services/6000, the number of attachments per adapter
depends on the designation of the attachment. While only one
attachment of designation "call" is permitted per adapter (PU),
SNA Services supports a maximum of 255 attachments of type
"listen" ("auto-listen"). If 255 attachments are active, only one
attachment can be used for dependent LU traffic. This is
because the Attachment Profile cannot specify its own XID node
ID - it must use the XID node ID specified in the Control
Point Profile.
SNA Server/6000 drops the use of the term "attachment", and
adopts the more conventional term "link station". Since each
Link Station Profile can specify its own XID node ID, SNA
Server/6000 supports a maximum of 255 link stations (PUs) per
adapter.
The "practical" limit is highly relative, depending on a number
of factors, including the applications running on the system.
Unfortunately, there are no "rules of thumb" to determine this
limit. I recommend that you contact the AIX Systems Center at
1-800-CALL-AIX.
2. See answer (1).
3. In SNA Services/60000, the number of active LU 6.2
connections is determined by the value of the "TOTAL active open
CONNECTIONS" in the Node profile. The maximum allowed (with
Quality Refresh 3) is 5000.
SNA Server/6000 equates a connection with a session (Local LU)
profile, thus the value is determined by the "Maximum number of
sessions" in the Node profile. The maximum here is also 5000.
If all the traffic is independent LU 6.2 traffic, both SNA
Services and SNA Server support any combination of LUs per PU
which totals 5000. If the traffic is dependent LU traffic, both
products support 255 LUs per PU.
4. There is no SNA architected limit on the number of
supported Token Ring adapters. The only limit is the maximum
number of adapters supported on the particular model of RISC
System/6000.
5. There are no other resource limits per Token Ring adapter.
But, note that you will probably need a great deal of real
memory in order to perform acceptably up to the maximum limits
mentioned above.
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This item was created from library item Q651511 CPFKF
Additional search words:
ARCHITECTED COMMUNICATIO CPFKF FEB94 IX LIMITS OZNEW RISC RISCSNA
RISCSYSTEM SESSION SNA SOFTWARE S6000
WWQA: ITEM: RTA000038147 ITEM: RTA000038147
Dated: 11/1996 Category: RISCSNA
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