1-24
Cisco 2900 Series and 3900 Series Hardware Installation Guide
OL-18712-02
Chapter 1 Overview of the Routers
Hardware Features
Power Supplies
Cisco 2900 series and Cisco 3900 series ISRs support a variety of power supply configurations. All
power supplies are field replaceable and externally accessible with the exception of the Cisco 2901 ISR.
The Cisco 2901 ISR has an internal power supply, which requires removing the cover for replacement.
If configured with dual power supplies or an Redundant power supplies (RPS), the power supplies are
hot swappable. RPSs require an RPS adapter. There are two versions of the RPS adapter, one for the
Cisco 2911 and one for the Cisco 2921 and 2951. Both use the Cisco Redundant Power System 2300.
Configurations include AC and DC (with and without IP), Dual DC, internal POE, and POE boost.
•
Table 1-9
summarizes the power options.
•
Table 1-10
shows POE power rates.
Cisco 3945
Type—VLP RDIMM with ECC
VLP RDIMM sizes—512 MB and 1 GB.
VLP RDIMM expansion slots—2; both must be the same density.
Default VLP RDIMM memory modules—Two 512-MB modules for a
maximum of 1 GB.
Maximum memory—2.0 GB; 1.0 GB in each slot.
Cisco 3925E
Type—VLP RDIMMwith ECC.
VLP RDIMM sizes—512 MB, 1GB.
VLP RDIMM expansion slots—2, both must be the same density.
Default ECC memory modules—Two 512-MB modules for 1 GB.
Maximum memory—2.0 GB; 1.0 GB in each slot.
Cisco 3945E
Type—VLP RDIMMwith ECC.
VLP RDIMM sizes—512 MB, 1GB.
VLP RDIMM expansion slots—2, both must be the same density.
Default ECC memory modules—Two 512-MB modules for 1 GB.
Maximum memory—2.0 GB; 1.0 GB in each slot.
Table 1-8
Router Memory Specifications (continued)
Router Platform
DRAM
Table 1-9
Cisco 2900 Series and Cisco 3900 Series Field Replaceable Unit Power Options
Router
Model
AC
AC +
POE
DC Hot Swap
1
Internal
RPS
2
External
RPS
3
Dual DC
4
Internal POE
Internal
POE Boost
External
POE Boost
5
2901
X
X
—
—
—
—
X
—
—
2911
X
X
X
X
—
X
—
X
—
X
2921
X
X
X
X
—
X
—
X
—
X
2951
X
X
X
X
—
X
—
X
—
X
3925
X
X
X
X
X
—
—
X
X
—
3925E
X
X
X
X
X
—
—
X
X
—