Cisco 2600/2600XM AND 3600 SERIES 8 PORT T1 ATM MODULE WITH IMA Specification Guide
Multiport T1/E1 IMA network modules functionality
allows access to ATM WAN uplinks with bandwidth
requirements between DS1 and DS3 rates. Each T1 link
provides 1.544 Mbps and each E1 link provides 2.048 Mbps
connectivity. With IMA’s aggregation of multiple T1/E1s,
network managers have the ability to increase bandwidth
inexpensively to allow wide-area network (WAN) uplinks at
speeds ranging from 1.544-Mbps to 16-Mbps full-duplex on
a single card.
All four multiport ATM network modules support the
ATM Forum Adaptation Layer 5 (AAL5) with ATM QoS
categories Unspecified Bit Rate (UBR), Variable Bit Rate
(VBR-rt and VBR-nrt), and Available Bit Rate (ABR). VoIP
and H.323 video over ATM can be supported using VBR-rt
class of service (CoS) parameters with the currently available
analog voice/fax network modules with voice interface cards
(VICs), or the new T1 digital packet voice trunk network
modules with multiflex trunk cards.
The multiport T1/E1 IMA modules’ support for VoIP
and H.323 video applications provides low latency, jitter-free
voice support to enhance throughput, and high-quality,
end-to-end voice and video performance. When combined
with high-density packet telephony solutions already
available on the Cisco 2600 and 3600 series, the multiport
ATM network modules provide a seamless end-to-end
multiservice solution, interoperable with other ATM Forum
IMA version 1.0 products available from Cisco.
Multiport T1/E1 ATM Network Modules:
New Features at a Glance
• Supported on all Cisco 2600 and 3600 series multiservice
platforms
• Supports four or eight T1/E1 ATM ports
• Support for ATM Forum IMA Version 1.0
• Up to 16-Mbps full-duplex bandwidth with an 8-port E1
IMA network module
• Supports UBR, VBR-rt, VBR-nrt, and ABR ATM CoS
• Maximum of four active IMA groups on both four- and
eight-port versions
• Integrated CSU/DSU on T1 versions
• Integrated DSU for E1 versions
• ATM Forum User Network Interface (UNI) 3.0, UNI 3.1,
and UNI 4.0 signaling
• ATM Adaptation Layer 5 (AAL5)
• Permanent Virtual Circuits (PVCs) and Switched Virtual
Circuits (SVCs)
• Request For Comments (RFC) 1483 support for multiple
encapsulations over ATM
• RFC 1577 support for Routing over ATM
• Maximum of 256 Virtual Circuits (VCs) per interface with
up to 1024 simultaneous reassemblies per card
• Maximum differential delay tolerance of up to 200-ms
• F4 and F5 Operation, Administration, and Maintenance
(OAM) cell support
• Cyclic Redundancy Check(CRC)32 error checking of
AAL5 and CRC10 checking of operations and
management (OAM) cells
• Internet Engineering Task Force (IETF) Point-to-Point
Protocol (PPP) over ATM
• Multiprotocol over ATM (MPOA) client and server
• LAN emulation (LANE) 2.0 client only
• Tag Switching (packet interfaces only)
• Interim Local Management Interface (ILMI)
• Next Hop Resolution Protocol (NHRP)
• ATM bandwidth (resource) manager
IMA Benefits
The multiport T1/E1 ATM offers the following benefits:
• Inexpensive ATM access
• A migration path to higher bandwidth without the need to
change transport facilities
• ATM Forum Version 1.0 standards compliant
(AF-PHY-0086.000) for multivendor interoperability
• Integrated CSU/DSU on T1 versions and integrated DSU
on E1 versions
• The addition and deletion of links without service
disruption
• Support for link failures and automatic link recovery
without loss of data
• Greater internetworking design flexibility and scalability
for LAN-to-WAN connectivity
• Efficient prioritization of mission-critical data provided by
ATM’s QoS features
• Simplifies network management
• Eliminates third-party inverse multiplexing devices