International standard for cell relay in which multiple service types (such as voice, video and data) are transmitted in fixed length cells (53 bytes). Offering a bandwidth of up to 622Mbps, theoretically up to 2.4 Gbps. The processing takes place in hardware, in order to reduce the delay in transit it. ATM is designed to take advantage of streaming media and high-speed E3/T3, and synchronous optical network (SONET). UTI ATM based broadband ISDN (BISDN). A coalition of companies formed the ATM Forum, which has created various specifications for ATM interoperability between devices from various manufacturers. Another feature of ATM is that it supports Guarantees Quality of Service (QoS).
The Cisco ATM interfaces are dedicated processor interface (or port adapters in a VIP card), which explains why it is not necessary to use the encapsulation command for your configuration. ATM virtual circuits offers connection-oriented, both permanent type (PVC) and dynamic (SVC), and also has an offline service that lets you operate like a LAN technology.
VPI and VCI numbers have only local importance, as is the case with the numbers DLCI in Frame Relay networks. ATM networks can use two different types of routing:
- E.164 addressing. Developed by the ITU for public ATM networks.
- Addressing NSAP. Developed by the ATM Forum for private ATM networks.
ATM Adaptation Layers (AAL) protocols are the top of the data link layer, responsible for providing various services to the protocols ATM network layer.
- AAL1. Connection-oriented service that is typically used to emulate dedicated circuits through the ATM network.
- AAL3 / 4. Pets oriented data both online and offline.
- AAL5. Pets also oriented services both online and offline, and is commonly used to transfer data over a LAN or private WAN.
Basic Configuration ATM Point to Point
Interface atm2 / 0
Atm pvc 1 0 100 aal5snap
Ip address 10.0.0.12 255.255.255.0
ATM interfaces, the type of command used to assign IP addresses to the data link layer protocol depends on the type and the type of ATM virtual circuits that have been used, as shown in the following examples of configuring multipoint interfaces .
The status of an ATM interface can be examined using the show interfaces command. To find the IP addresses of ATM multipoint interfaces, we can use the show atm map command.
Multipoint ATM Interface Configuration - LLC / SNAP PVC
Router (config) # interface atm 1 / 0
Router (config-if) # atm pvc 3 0 21 aal5snap
Router (config-if) # atm pvc 5 0 22 aal5snap
Router (config-if) # ip address 255.255.255.0 131.108.104.1
Router (config-if) # Map-group ZIP1
Router (config-if) # Map one zip-list
Router (config-map-list) # ip 131.108.104.2 atm-vc 3 broadcast
Router (config-map-list) # ip 131.108.104.7 atm-vc 5 broadcast
Multipoint ATM Interface Configuration - LLC / SNAP SVC
Router (config) # interface atm 1 / 0
Router (config-if) # atm NSAP
FE.DCBA.01.987654.3210.ABCD.EF12.3456.7890.1234.12
Router (config-if) # ip address 255.255.255.0 131.108.104.1
Router (config-if) # map-group ZIP1
Router (config-if) # map-list ZIP1
Router (config-map-list) # ip 131.108.104.2 atm-NSAP
A1.9876.AB.123456.7890.FEDC.BA.1234.5678.ABCD.12
Router (config-map-list) # ip 131.108.104.7 atm-NSAP
B2.9876.AB.123456.7890.FEDC.BA.1234.5678.ABCD.12
Multipoint ATM Interface Configuration - IP with ARP
Router (config) # interface atm 1 / 0
Router (config-if) # atm NSAP
FE.DCBA.01.987654.3210.ABCD.EF12.3456.7890.1234.12
Router (config-if) # ip address 255.255.255.0 131.108.104.1
Router (config-if) # atm arp-server NSAP
01.abcd.22.030000.0000.0000.0000.0000.0000.0000.00