Packetization buffers and queues are supported in the packet memory of each adapter card or platform. All adapter cards and platforms allocate a fixed space for each buffer. The 7705 SAR supports two buffer sizes: 512 bytes or 2304 bytes, depending on the type of adapter card or platform.
The adapter cards and platforms that support a buffer size of 2304 bytes do not support buffer chaining (see the description below) and only allow a 1-to-1 correspondence of packets to buffers.
The adapter cards and platforms that support a buffer of size of 512 bytes use a method called buffer chaining to process packets that are larger than 512 bytes. To accommodate packets that are larger than 512 bytes, these adapter cards or platforms divide the packet dynamically into a series of concatenated 512-byte buffers. An internal 64-byte header is prepended to the packet, so only 448 bytes of buffer space is available for customer traffic in the first buffer. The remaining customer traffic is split among concatenated 512-byte buffers.
The following table shows the supported buffer sizes on the 7705 SAR adapter cards and platforms. If a version number or variant is not specified, this implies all versions of the adapter card or variants of the platform. Adapter cards and platforms that support buffer chaining have 512 byte buffer size (‟Yes”); those that do not support buffer chaining have 2304 byte buffer size (‟No”).
Adapter Card or Platform |
Buffer Space per Card/Platform (Mbytes) |
Buffer Chaining Support |
|---|---|---|
2-port 10GigE (Ethernet) Adapter card |
268 201 (for L2 bridging domain) |
Yes Yes (each buffer unit is 768 bytes) |
2-port 10GigE (Ethernet) module |
201 (for L2 bridging domain) |
Yes (each buffer unit is 768 bytes) |
2-port OC3/STM1 Channelized Adapter card |
310 |
No |
4-port OC3/STM1 / 1-port OC12/STM4 Adapter card |
217 |
Yes |
4-port OC3/STM1 Clear Channel Adapter card |
352 |
No |
4-port DS3/E3 Adapter card |
280 |
No |
6-port E&M Adapter card |
38 |
No |
6-port FXS Adapter card |
38 |
No |
6-port Ethernet 10Gbps Adapter card |
1177 |
Yes |
8-port FXO Adapter card |
38 |
No |
8-port Gigabit Ethernet Adapter card |
268 |
Yes |
8-port Voice & Teleprotection card |
38 |
No |
8-port C37.94 Teleprotection card |
38 |
No |
10-port 1GigE/1-port 10GigE X-Adapter card |
537 |
Yes |
12-port Serial Data Interface card, version 2 and version 3 |
268 |
Yes |
16-port T1/E1 ASAP Adapter card |
38 |
No |
32-port T1/E1 ASAP Adapter card |
57 |
No |
Integrated Services card |
268 |
Yes |
Packet Microwave Adapter card |
268 |
Yes |
7705 SAR-A |
268 |
Yes |
7705 SAR-Ax |
268 |
Yes |
7705 SAR-H |
268 |
Yes |
7705 SAR-Hc |
268 |
Yes |
7705 SAR-M |
268 |
Yes |
7705 SAR-Wx |
268 |
Yes |
7705 SAR-X (Ethernet ports)1 |
1177 |
Yes |
7705 SAR-X (TDM ports) 1 |
46 |
Yes |