Applications Using Dynamic Tcam Infrastructure; Features Using Tcam Resource - Juniper ACX1000 Configuration Manual

ACX Series Universal Access Router Configuration Guide

Applications using Dynamic TCAM Infrastructure

Features Using TCAM Resource

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space limits. The allocation of TCAM resources for various filter applications are statically
distributed. This static allocation leads to inefficient utilization of TCAM resources when
all the filter applications might not use this TCAM resource simultaneously.
The dynamic allocation of TCAM space in ACX routers efficiently allocates the available
TCAM resources for various filter applications. In the dynamic TCAM model, various filter
applications (such as inet-firewall, bridge-firewall, cfm-filters, etc.) can optimally utilize
the available TCAM resources as and when required. Dynamic TCAM resource allocation
is usage driven and is dynamically allocated for filter applications on a need basis. When
a filter application no longer uses the TCAM space, the resource is freed and available
for use by other applications. This dynamic TCAM model caters to higher scale of TCAM
resource utilization based on application's demand.
The following filter application categories use the dynamic TCAM infrastructure:
Firewall filter—All the firewall configurations
Implicit filter—Routing Engine (RE) demons using filters to achieve its functionality.
For example, connectivity fault management, IP MAC validation, etc.
Dynamic filters—Applications using filters to achieve the functionality at the PFE level.
For example, logical interface level fixed classifier, RFC 2544, etc. RE demons will not
know about these filters.
System-init filters—Filters that require entries at the system level or fixed set of entries
at router's boot sequence. For example, Layer 2 and Layer 3 control protocol trap,
default ARP policer, etc.
NOTE: The System-init filter which has the applications for Layer 2 and
Layer 3 control protocols trap is essential for the overall system
functionality. The applications in this control group consume a fixed and
minimal TCAM space from the overall TCAM space. The system-init filter
will not use the dynamic TCAM infrastructure and will be created when the
router is initialized during the boot sequence.
Applications using the TCAM resource is termed tcam-app in this document. For example,
inet-firewall, bridge-firewall, connectivity fault management, link fault management,
etc., are all different tcam-apps.
Table 82 on page 1159 describes the list of tcam-apps that use TCAM resources.
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