Merge pull request #7269 from tmorriso-rh/PR-5049-IPSec-statement

Fixed incorrect statement about IPSec throughput

Author: Traci Morrison

scaling_performance/network_optimization.adoc

@@ -58,8 +58,8 @@ in latency tests.
 [[scaling-performance-optimizing-mtu]]
 === Optimizing the MTU for Your Network
 
-There are two MTUs (maximum transmission units) that matter: the network
-interface card (NIC) MTU, and the SDN overlay's MTU.
+There are two important maximum transmission units (MTUs): the network
+interface card (NIC) MTU and the SDN overlay's MTU.
 
 The NIC MTU must be less than or equal to the maximum supported value of the NIC
 of your network. If you are optimizing for throughput, pick the largest possible
@@ -97,7 +97,7 @@ can also be set to any other CNI-compatible plug-in as well.
 default values allow for:
 
 - Maximum cluster size of 1024 nodes
-- Each of the 1024 nodes has a /23 allocated to it (510 usable IPs for pods)
+- Each of the 1024 nodes has a /23 allocated to it (510 usable IP addresses for pods)
 - Provides 65,536 IP addresses for services.
 
 Under most circumstances, these networks cannot be changed after deployment.  Thus it is important to plan ahead for growth.
@@ -114,7 +114,7 @@ Ansible inventory file:
 osm_cluster_network_cidr=10.128.0.0/10
 ----
 
-This will allow for 8192 nodes, each with 510 usable IPs.
+This will allow for 8192 nodes, each with 510 usable IP addresses.
 
 See the supportability limits in the {product-title} documentation for node/pod limits for the version of software you are installing.
 
@@ -125,6 +125,7 @@ Because encrypting and decrypting node hosts uses CPU power, performance is
 affected both in throughput and CPU usage on the nodes when encryption is
 enabled, regardless of the IP security system being used.
 
-IPSec encrypts traffic at the IP level, before it hits the NIC, protecting
+IPSec encrypts traffic at the IP payload level, before it hits the NIC, protecting
 fields that would otherwise be used for NIC offloading. This means that some NIC
-acceleration features may not be usable when IPSec is enabled and will lead to increased throughput and CPU usage.
+acceleration features may not be usable when IPSec is enabled and will lead to
+decreased throughput and increased CPU usage.