additional network memory

additional network memory sets the amount of additional memory allocated to the network memory pool.

Summary Information
Default value	0
Range of values	0 – 2147483647
Status	Dynamic
Display level	Intermediate
Required role	System administrator
Configuration groups	Memory Use, Network Communication, Physical Memory

You must increase the size of the network memory pool if you configure the max network packet size greater than the default network packet size. SAP ASE rounds down the value you enter to the nearest 2K value.

When a login requests a large packet size, SAP ASE verifies it has sufficient memory available to satisfy the request. If it does not, SAP ASE finds the largest available block of memory and tries the appropriate size (which is a multiple of default network packet size) less than the largest memory block. If that fails, SAP ASE decreases the value of the request by the number of bytes equal to default network packet size, if this is available. SAP ASE continues for 10 iterations, or until the size equals the value of default network packet size, whichever comes first. On the tenth iteration, SAP ASE uses the value of the default network packet size for the packet size.

SAP ASE guarantees that every user connection can log in at the default packet size. However, if you increase max network packet size, you must also increase the value for additional network memory.

Note: Users may be able to connect to SAP ASE with a larger packet size with additional network memory set to zero because of system-configured overhead in the network memory pool.

If you increase max network packet size but do not increase additional network memory, SAP ASE does not guarantee that clients who request network packet sizes larger than the default size can login at the requested packet size.

Increasing additional network memory may improve performance for applications that transfer large amounts of data. To determine the value for additional network memory when your applications use larger packet sizes:

Estimate the number of simultaneous users who will request the large packet sizes, and the sizes their applications will request,
Multiply this sum by three, since each connection needs three buffers,
Add two percent for overhead for 32-bit servers, or four percent for 64-bit servers, and
Round the value to the next highest multiple of 2048.

For example, if you estimate these simultaneous needs for larger packet sizes:

Application	Packet size	Overhead
bcp	8192
Client-Library	8192
Client-Library	4096
Client-Library	4096
Total	24576
Multiply by 3 buffers/user	* 3=73728
Compute 2% overhead		* .02=1474
Add overhead	+ 1474
Additional network memory	75202
Round up to multiple of 2048	75776

Set additional network memory to 75,776 bytes.