Eagle: Why Is The Range Of ISTRMS (Inbound Streams) & OSTRMS (Outbound Streams) Values 1-2 When These Are 16-Bit Integers

Asset ID:	1-71-2381804.1
Update Date:	2018-04-03
Keywords:

Solution Type Technical Instruction Sure

Solution 2381804.1 : Eagle: Why Is The Range Of ISTRMS (Inbound Streams) & OSTRMS (Outbound Streams) Values 1-2 When These Are 16-Bit Integers

Applies to:

Oracle Communications EAGLE (Software) - Version EAGLE 44.x and later
Tekelec

Goal

To clarify why the range of ISTRMS and OSTRMS parameters in chg-assoc command is 1-2 when, as per the Commands Users Guide(https://docs.oracle.com/cd/E86948_01/docs.465/E83005_rev_1.pdf - pag. 148), these are 16-bit integers. A 16-bit integer could allow a wider range than 1-2.

istrms:
SCTP Inbound Stream Value. A 16-bit unsigned integer that defines the number of
streams the sender allows the peer end to create in this association.
Range:
1 - 2

ostrms:
SCTP Outbound Stream Value. The 16-bit unsigned integer that defines the number
of streams the sender wants to create in this association.
Range:
1 - 2

Solution

According with RFC4960 both the values of inbound and outbound streams are occupying 16 bits in an INIT/INIT-ACK chunks and indeed the decimal value could exceed the values that Eagle documentation specifies for that command.

However, there are several architectural issues regarding the use of multiple streams as described in the SCTP protocol, issues that can be related to:
• Synchronization between data streams
• Synchronization from control stream to data streams
or
• Load-sharing implementation across streams

Since there is a lack of consensus on the IETF SIGTRAN mailing list regarding these issues this resulted in supporting a maximum of two streams.

Attachments

This solution has no attachment