CISCO1921/Cisco 1941 is to replace the very popular Cisco 1841 router. Cisco 1841 is no longer being sold and might not be supported. Cisco 1921, new licensing and software, (probably) better performance and support for new modules–it dominates the Cisco 1841 and previous generations of branch office routers.
So here let’s have an overview on Cisco 1841 and CISCO 1921, to find out the main difference between them. Why Cisco 1921 is the best replacement for Cisco 1841 router today?
CISCO1841-The Current Standard 1RU, 19 inch rack mountable, single power supply, 256 MB DRAM and 64 MB internal flash. 75,000 PPS (35Mbps w/ 64 byte packet size) performance 2x Fast Ethernet (10/100) ports (RJ45) 2x HWIC slots (but only one FE or GE HWIC may be used at a time)
The Cisco 1841 has an integrated VPN processor for IPsec VPN and the option to add an AIM card for SSL VPN capabilities, but the 1841 has no voice capabilities–it is not suitable for voice gateway or call manager applications. However, if you have a SIP trunk or other VoIP data connection, the 1841 does support passing VoIP packets through, as well as very robust QoS to prioritize the VoIP traffic.
CISCO1921-The Next Generation Router
1 RU, 19 inch rackmountable, single power supply, 512 MB DRAM, 256 MB internal flash
15MBPS quoted performance “with services enabled”, likely much faster straight throughput
2x 10/100/1000 Ethernet ports (RJ45)
2 EHWIC slots
The Cisco1921/k9 router has integrated IPsec and SSL VPN support with upgraded software, but like the Cisco 1841, the Cisco 1921 cannot be used as a Call Manager or voice gateway (but can still pass VoIP packets through).
New and Simplified Software
The new routers now use license keys and a universal image to determine the available features, in the same manner as a PIX or ASA.This new licensing scheme also has the benefit of producing a clear division between the version of IOS installed and the feature set installed, so you can update the IOS version without touching the feature set part, or upgrade the feature set on a router without touching the IOS file.
In addition, the licensing structure has been further streamlined, now leaving us with just 3 features sets, none of which overlap.
Here are the contents of each available feature package:
IP Base: The default feature set; has support for common routing protocols (RIP, OSPF, EIGRP, BGP), common WAN technologies (MLPPP, MLFR), and common LAN technologies (802.1q trunking). No VPN, firewall, or voice features are present.
Data: The Data license adds support for MPLS, ATM, IS-IS, and non-IP L3 protocols.
Security: The Security feature set adds IPSec VPN capabilities, SSL VPN capabilities, and IOS firewall features.
You can apply any combination of these feature sets to the router; you are not restricted to a single feature set per device.
The 1921 router also has much-improved system architecture, with the EHWIC slots now having a high-throughput point to point connection, vs. the old bus-based architecture of the previous routers.
So Cisco 1921 router is a fantastic device, but with similar limitations to its predecessors-it has only a single power supply and no feature set for voice.
For those that really need the last degree of performance, however, and can live with its limitations it is a good evolutionary step forward from previous generations of small routers.